>had they been supporting old hardware, software on new hardware would have been measurably worse
Might not have been measurable, and might just cost an extra engineer without really harming anything.
If they had gone 64-bit-only, I'd be much more in agreement with you. But if you're still supporting a 32 bit platform, you have a lot of restrictions put on you, and the marginal cost of keeping support for a second 32 bit platform is not a big deal.