Possible, but that stuff is mostly artificial and performance-targeted. To take another example from the Mac world, Apple's hardware requirements have almost always been artificially inflated, with people having great success in applying gentle tweaks to make them run on older computers.
Anyway, you certainly could build something that really can't run on older stuff, or can't run well. My point is merely that the dilemma you propose is wrong: there are at least three options (don't support old stuff, support old stuff badly, support old stuff well), not just two.
Anyway, you certainly could build something that really can't run on older stuff, or can't run well. My point is merely that the dilemma you propose is wrong: there are at least three options (don't support old stuff, support old stuff badly, support old stuff well), not just two.