It's not a contradiction if you assume that (a) language choice is critical and (b) rewrites are doomed to be failures.

Having that said I agree that language/platform is a "non technical requirement" in 90% of real world cases. You pick what you know or in more industrious scenarios - what's available on the market or what's the most cost effective.

But people are indeed irrational about programming languages. There's tribalism, stereotypes and preconceptions. Most notable is probably PHP, language for human failures and shit projects. As if same exact project written in Java was suppose to be of higher philosophical value.

But it's something you can't deny. I've been asked in non ironic way by a (non technical) founder investor if I could recommend him Rails programmers, because he read about it and it's suppose to be great. I asked him about specifics of his new project and he said he doesn't have an idea yet, but it has to be in Rails. Go figure.