Indeed, but using shoddy lenses (by comparison I mean; I don't know any 70-300s which are a patch on a good 70-200, which is why they are much more expensive) will just show up even more if you crop harder. So the guy will get a better body, and then realise he needs a new glass shortly after.
I think the real solution to this issue is better glass. Faster, better quality glass such as a 70-200 f/2.8 will allow higher shutter speeds, more subject seperation as well. You could stick a 1.4x on the 70-200, and STILL have the advantage! I don't believe in spray n' pray at the worst of times, (and I think high FPS bodies just encourage sloppy behaviour) but with a better glass, it shouldn't be needed, negating the need for a better body.