I doubt it's true. I think it would be relatively easy to find technically sophisticated people who're unaware of Kurzweil's specific predictions; it'd be harder to find technically sophisticated people who're consistently unaware of his general thesis, but I'll bet you could still do it. You'd just need to look outside the transhumanist/singularitarian/AI enthusiast cluster.

Since those clusters are pretty tightly grouped in terms of conceptual underpinnings, it should be easy to filter them from a sample. Getting a good sample would be harder -- LW wouldn't do it, and personal blogs wouldn't either. Gwern's idea below looks promising but I have no idea how you'd go about it.