Imo you're not missing something that is there, but seeing something that is not there, namely the cogency of the reply to the Fine-tuning Argument which appeals to the Weak Anthropic Principle. The argument starts from the observation that the universe supports the existence of intelligent life; the reply is that the universe necessarily supports the existence of intelligent life, else we wouldn't be here to articulate arguments based on observations, and that this observation is sufficient to explain the fact that the universe supports the existence of intelligent life. Those who use this reply against Aquinas's Fifth Way (the Argument from Final Causality) are thus essentially saying that the universe supports intelligent life because the universe supports intelligent life, which is nonsense; nor can this circularity be avoided by claiming that ours is perhaps just one of many 'universes,' so that to observe that ours just 'happens' to support intelligent life is an example of survivor's bias; for there is no reason to assume a priori, absent any theological data, that any actually existing universe should play host to intelligent life, and, besides, the very concept of a plurality of universes, of 'many everythings,' is incoherent. (The talk of 'many infinities' or 'many kinds of infinity' in modern mathematics is due to the indifference of mathematicians to the traditional meanings of words—ultimately, to the unfortunate lack of culture among modern scientists generally, which proceeds from hyper-specialization necessitated by information accumulation—and not to any factor intrinsic to the content of the theories themselves.)
These objectors, like those who, in reply to the Second Way (Argument from Efficient Causality), say that there is no reason why we cannot regress from effects to their causes forever, never arriving at an absolutely first Cause, confuse the 'order of being' (ordo essendi) with the 'order of knowing' (ordo cognoscendi).' The objectors to the Second Way forget that, though, due to our reliance on our bodies and their passive sense-organs for perception, we often know effects before we can conjecture their efficient causes, yet the existence of an efficient cause necessarily precedes the existence of its effects, since an efficient cause is precisely the cause of its effects insofar as they exist, and that, therefore, this regress from effects to their causes is merely a reversal in thought of the progress from causes (indeed, a single first Cause) to their effects which takes place in reality. The objectors to the Fifth Way, similarly, forget that, though we know ourselves as intelligent beings long before we arrive at the concept of intelligent life in general, yet our existence does not explain how the existence of intelligent life in general is possible—it simply proves that it is possible and moreover actual.
This scholastic distinction between the order of knowing and the order of being may seem pedantic, but it is really just an explicit expression of a tacit commonsense principle: smoke tells us that the fire is there, but it doesn't tell us how it got there, why the fire. Of course, we might not care how the fire got there, but we cannot be indifferent as to the source of our own being without denying our very nature as rational beings, to whom it is proper to look for reasons, for science (i.e. demonstrative knowledge of things, knowledge of things through their causes), and especially for the meaning of our own lives. The first Cause, which we call God, is thus the object of the deepest yearning of human nature. Who will be so perverse as to say that he doesn't believe in Him?
