No. Religious doctrine is most often pure dictate. Scientific theory is a hypothesis supported by evidence.
"I see no reason why science not could consider both "life on Earth was created spontaneously out of primordial ooze" and "life on Earth was created by an intelligent being". The former statement is at most a hypothesis; there is nothing substantial to prove it.
No one has a good enough idea to teach any kind of abiogenisis outside of college. The hypothesis says nothing more than life somehow came about naturally. That's it. This intelligent being stuff is not science whatsoever. I've already posted what the proper subject for science is. If you want to have the forces of the designer taught, bring him in for examination, so we can quantify his action and motivations. Else, he's stays in the religious class.
" Even if one believes there is no substantial evidence to prove the latter, it doesn't make it less scientific to investigate the possibility - it's certainly favored by Occam's Razor."
The latter is not a proper scientific subject, nor is it favored by Occam's razor. Occam's razor: "one should not increase, beyond what is necessary, the number of entities required to explain anything." The physics is sufficient.
But there's no evidence that says life arose spontaneously from organic chemicals rather than any other way, either. If you define that as "nature", then you are basing your judgement on an unproveable belief of what nature is - which is exactly what religious doctrine does. A truly objective scientist can accept neither one as incontrovertibly established fact.
Why is it scientifically inconceivable that, if not God, some elder, sentient, and spacefaring race created Man and deposited us here, on a world suited to our needs? There's no evidence of that, but there's no evidence that life spontaneously generated here either.
I'm using the words "spontaneous" and "generated" here because the idea that life was created by chance out of non-living molecules is very similar to the last theory known as spontaneous generation. Seems sensible from a practical point of view, but that's not necessarily the case in reality.
With respect to spontaneous generation as the creator of life on Earth, to me - and I think also to our hypothetical objective scientist - that is no less fantastic than aliens or God as an explanation.