The whole point of this patch was to deal with old (~7 W h) batteries. Your 2000-era PC was usually plugged directly into the power grid, or if it was a laptop, it had a 50 W h battery and went a few hours away from grid power at most.

It's a lot easier to "not write slow software" if you're not constrained by power limitations. Apple went to all the trouble of switching CPU architectures just to get on a better side of that problem.