I think you are underestimating peoples willingness to go with a clean slate. I mean look at the chain of events.
1) Twelve Colonies Nuked
2) New Caprica taken over
3) Earth is a cinder
4) An armed insurrection in the military
5) the final battle with Cavil's cylons
You pile those huge events and just being stuck on a ship for four years, anyone would trade away technology for just a quiet slice of heaven.
Also I doubt that any raptors or vipers would of survived 150,000 years of erosion. Even at best I think the models say that if humanity left right now, most buildings would last 1000 years tops.
Well, impossible to say with certainty, as I have neither survived a civilization-ending apocalypse, nor do I know anyone who has.
I am reminded here of the old saying; guns don't kill people, people kill people. Humans have the capacity to wipe each other out regardless of the tech level. High-tech just makes it easier.
Now, let me plug in a real-world analogy here. Here, in the United States we have a very wide spectrum. We have people like you and I, who choose to spend considerable on the net, posting, gaming and whatever else we do here. On the other hand we have US citizens like the Amish that choose to live with simpler ways.
I can't see the remaining human population subscribing wholesale to this idea without even so much as a vigorous debate. Much more likely, I can see a schism where the various groups spread out, and some may have adapted to simpler ways and others did not.
Even going low-tech makes no assurances: At an Amish-level of technology I can use my axe to fell a tree and raise a barn, or lay it upside someone's head. It's not the technology, it's the mind that wields it.
I can say I'd never be willing to relinquish my level of technology- it's not just about the conveniences, after lots of research on the topic, I am thoroughly convinced that high-tech is going to help save all our asses in the real world. Going to improved transpiration and housing, alternative and renewable energy sources, and taking the massive strain off the planet we're in danger of ruining.
Like I said, I'll help you hunt mammoth...right after I get my laser gun.
As far as the technology goes, if Hera can be found as a fossil and soft tissue can be found inside Tyrannosaurus bones after 65+ million years in the ground (an actual documented find), then they could find Raptors or Vipers.
Sure, they'd mostly disintegrate over 150,000 years, but even if the colonists deliberately destroyed their ships, unless they flew them all into the sun, anything on the ground would leave remains. Paleontologists and archeologists would find anomalous metal alloys they couldn't explain, incongruous to the local geology. In fact, coming from who knows how far away in the galaxy, the ships' remains might even contain elements we donít know of on earth. Or, isotopes known by modern humanity on Earth, when found, may reveal half-lives that match nothing terrestrial, making it possible to not only date the relics, but determine they are of extraterrestrial origin. Even bits and pieces are likely to reveal signs of artificial manufacture.
And it doesnít even have to be a colonial spacecraft; a toaster that survives in the strata layers (an actual toaster, not a Cylon) would still possibly have enough remains to reveal itself as a relic from a previous technology level.
And youíre correct; if humanity just up and stopped right now; most of what we have built will have collapsed within a millennium. However, the materials we built them with, relics of our modern day, would endure for a very long time. Enough to prove that we were here.
So there, I've had my uber geek moment and picked the final plot apart on surgical scale, but I've examined what makes sense.