Let's go back to the original question. The question is why assume that intelligent life is more valuable than a rock? The question is raised in the context of the fine tuning argument. I will, therefore, assume that the person posing the question means to suggest that the fine tuning argument necessarily makes the assumption that life is more valuable than rocks. This is false.
One proposed example of fine tuning is that the expansion rate of the universe must be exquisitely balanced to avoid either the quick collapse of the universe shortly after it comes into existence or to avoid matter being so widely dispersed that stars and planets cannot form. If such a balance did not exist, life could not exist. It would be equally true to say that not only could life not exist, but ordinary objects could not exist such as rocks or tables.
Another proposed example of fine tuning involves the balance of the strong nuclear force and the weak nuclear force that is necessary for heavier elements to form. Again this fine tuning is necessary for the universe to be "life-permitting" or "rock permitting". Therefore, the observation that the universe is fine-tuned is value neutral as to whether life is more valuable than rocks.
It is true that the argument is usually framed in terms of life-permitting universes. As Dr. Craig explains in the debate you cite:
"Now all of these constants and quantities fall into an extraordinarily narrow range of life-permitting values. Were these constants or quantities to be altered by even a hair’s breadth, the life-permitting balance would be destroyed and life would not exist. We now know that life-prohibiting universes are incomprehensibly more probable than any life-permitting universe."
He could just as well as framed the argument as "the fine-tuning refers to narrow range of values that permits planets and heavy elements to exist that would be necessary for life or any ordinary physical object such as tables to exist". It does not require any type of assumption that intelligent life has a special value.
So why does Dr. Craig choose to frame the argument in terms of "life permitting" universes rather than as "object permitting" universes. Nothing in his argument requires that he do so. Does he have some deceptive reason? I don't think so. As ontologicalme observes most people intuitively assume that life is more valuable than rocks so it is not unreasonable to frame the argument in such terms, although it is not necessary.
I agree with your claim that the existence of fine tuning, by itself, does not lead to any conclusions about the existence of God. The concept is value neutral and theologically neutral. That is why Craig does not end his argument with the mere assertion that the universe is fine tuned. He goes onto to argue for several other premises, which are:
1) This fine tuning can only be explained by chance, necessity or design;
2) It cannot be explained by chance;
3) It cannot be explained by design:
Therefore, it can only be explained by design.
Now you raise a number of arguments related to whether the universe is fine-tuned as described by Dr. Craig or whether the multiverse theory would allow a life-permitting universe to exist by chance. You are free to raise such arguments, but they are red-herrings as to the issue being discussed in this thread. If you want to discuss such issues, perhaps you should start a new thread on the topics, "The universe is not fine-tuned" or "The multiverse is an explanation how fine-tuning can be explained by chance."
The last point I would make is that if you want a full presentation of the fine tuning I would not rely on Dr. Craig's debate transcripts because they are necessarily time limited and focused on the arguments raised by his opponents. They are necessarily very incomplete defenses of the argument. If you go to the transcripts of the defenders series or articles of Dr. Craig you will find much more complete presentations. Better yet, I would suggest Dr. Robbin Collins book on the topic.
Paul your whole argument relies on a mistaken made this sentence you made:
“I will, therefore, assume that the person posing the question means to suggest that the fine tuning argument necessarily makes the assumption that life is more valuable than rocks. This is false.”
Firstly it isn’t about what the argument necessarily implies, it’s about how the argument is used to convince people of god. If someone said the universe was fine tuned to allow for table tennis therefore god exists people wouldn’t take that seriously. One could create a theology whereby god’s main purpose in creating the universe is to watch people play table tennis. So he fine tunes all the constants, steers the evolution of life and the evolution of sport all to the grand objective of watching table tennis matches from heaven. Since as far as I know no one believes such a theology such an argument would not be convincing. Just as it would not be convincing for rock or cup cakes.. But people do believe that god created the universe for human being to exist and it’s crucial that this is how the argument is framed as the fine tuning argument for life otherwise the argument will fall flat. I think you are living in denial if you think otherwise.
if you study the universe and appreciate its grand scale, you may realise the life is a tiny blip in a see of vacuum, there’s no reason though think its special as a phenomenon in the universe. Moreover if the constants of nature were different maybe other phenomenon would arise, phenomenon we’ve never even dreamed of. This is why Roger Penrose said :
“The main thing that I am not happy about is that I don't see how we have the remotest idea what would happen in a world where the constants of nature were different “
Alan Guth says something very similar in the video link I posted above. Did you watch it?
When we look at the universe today we see it’s dominated by phenomenon that isn’t even described by the standard model. Only 4-5% of the universe is accounted for by baryonic matter that is described by the standard model. Dark matter isn’t in the standard model, neither is dark energy. No one knows what these things are. Is the universe fine tuned for the existence of dark matter? No dark matter and life wouldn’t form. We need dark matter for galaxies to form. So given what we know there is crucial phenomenon in our universe that we couldn’t have ever predicted from the standard model , its ridiculous in the extreme to suppose we know what other phenemonon would arise in a universe with different constants, we cant even predict what arises in this universe.
Another difficulty you face if you are a Christian theist, is that Christian theists believe that god created life via a miracle, now if that’s true then its false that the values of constants need to be fine tuned , if the values of the constants were different would god have been unable to create life? If yes then god is not omnipotent, if no then they don't need to be fine tuned. You can’t have it both ways.
Paul when you say the expansion rate of the universe needs to be specially balanced are you referring to the Hubble parameter or omega sub zero? When I was at college there was a huge debate about whether the Hubble parameter was 50 or 100, Planck gave us a value of 67.3 so it hardly seems fine tuned. So I presume you mean omega sub zero, is that right?
With regards to my arguments being red herring, they would have been if you hadn’t raised the issue of the validity of the fine tuning argument. But since you did, they are not. So perhaps you could address them.