It's not, as the ID advocates claim, a case of narrow-minded intolerance for alternatives. Alternative explanations for the proliferation of life on earth (or for any other natural phenomenon) are allowed, provided -- as in your example of cosmology, or any other science -- they can fit the existing evidence. And provided further, as with any scientific hypothesis, such an alternative explanation leads to some kind of prediction that would distinguish it from the current theory. (As the cosmic background radiation did in the days when Steady State was a competing theory.)
As it is, given the chronological fossil record, and then the amazingly consistent picture that the DNA evidence provides, it's been rather difficult (an understatement) to take the immensity of that evidence and rearrange it into any coherent scenario other than the one that evolution provides. It's true that where gaps still remain in the record (and I assume there will always be some gaps) one can imaginatively insert any desired causal agent. But does such a conjecture lead to any testable observations? So far, the ID camp has failed to come up with anything -- thus the "intolerance" for what is rightly seen as an unscientific proposal.
With an equal dose of imagination, I could assert that the hemisphere of a planet that faces away from us has a big smiley face on it, which always moves out of sight when the planet rotates that side toward us. I can make such a claim because there's aways a "gap" in our observational ability where my smiley face may exist. But to me, that's not much of an alternative theory.
Catch you later!
You assert that the intolerance for intelligent design hypotheses is because they do not result in testable or observable predictions. I cannot speak for the fellows at Discovery.org - but I have been offering one around here for a couple of years which is both observable and falsifiable:
The Euclid algorithm includes processes, symbols, decisions and recursives and is purposeful. Decision making, awareness and purpose are properties of intelligence - therefore such properties existing at the inception of a thing (whether entirely internal as in initial rules for self-organizing complexity or whether externally interfaced as in communications) indicates an intelligence causation.
Falsifications: (a) evidence that there is no algorithm at inception, (b) evidence that there was no inception, (c) evidence that decision-making, awareness and purpose are not properties of intelligence.
Concerning life v non-life/death in nature, evidence one way or the other will emerge from the current research in self-organizing complexity and information theory (successful communications) in biological systems: e.g. what are the minimum rules, state changes, mathematical structures, geometries and whether they have [Euclid] algorithmic properties of decision-making including purpose and awareness.