You can't speak for "Linux users" in general, that's a community of too diverse people. The richest ones probably have better computers than the poorest ones. There is no such thing as "price sensitivity", there is only money and priorities for spending the money.
If you're complaining about Linux programmers worrying about old computers, then you're crazy, not everybody is as rich as you. And this rationale that Linux doesn't work on better computers doesn't make any sense.
Also, why do you care so much that Linux gets more widespread? Does it yield a lot of benefits to you to have your neighbor using Linux instead of Windows? Linux is already much more widespread today than probably ever.