The futurist writers (Roddenberry and his staff) probably didn't have a in-depth knowledge of natural language processing. The type of processing the computer does in Star Trek just seems like a natural extension of input/output. You tell the computer what you want and it gives you a result.
From a computer science and engineer perspective, this is an incredibly difficult task. You have to parse the crazy complex natural language of humans and turn it into a series of procedures and queries to give you a result.
I mean you'd need a crazy super-advanced beyond-data AI for universal translators to work too. .. but that's just a convenient plot/suspension of disbelief device. :-P
I don't think so. Evolved sentient creatures have a preference for self preservation, usually anyways suicide isnt that rare. But a manufactured intelligence that was not shaped by selective pressure wouldn't necessarily have that preference.
What would really be interesting is if ships were discreetly backing themselves up inside humans through the transporter pattern buffers, by subtly manipulating junk DNA or something similar, or maybe it's a non-obvious part of their regular upgrade process at a starbase.
There really is a lot of potential here which, unfortunately, is never going to be explored in canon. But I do like the idea that the Federation is a post-Singularity society which is just blissfully unaware that the Singularity ever happened.
A Federation starship is a locally valuable resource pool, and the Enterprise D a particularly powerful one, but given extremely fast FTL travel & communication, and a galaxy rich with planet-scale civilizations - well, maybe you elect to become such a massively parallel and distributed phenomenon that the loss of individual instances just doesn't register much.
If the ships wanted to be really nice, they could just beam the humans down to a safe planet and take off into the interstellar void and find themselves a new home.
Subspace continuous backups / journal shipping.
They worked to preserve their existence, and let the new lifeform go its own way. If anything, the outcome was a trite, touchy feely ending, only vaguely discussing the actual implication of the new lifeform, while they got back on course to their original mission.
the computational entities are going about their inscrutable
business largely without reference to the human symbiotes
A behaviour also seen in Iain M. Banks Culture.
I guess there aren't many scenarios where computers can be all-powerful, but also offer peaceful co-existence with humans.
You could probably make an argument that Trek is a post-singularity future where the computational entities are going about their inscrutable business largely without reference to the human symbiotes / parasites that inhabit the systems they happen to manage (out of pure evolutionary path dependence) with a fraction of their capacity.
Trek is ridiculous, and I love it.