The opposite effect always feel like magic. I have fond memories to see one CGI software making my old Pentium2 350 do real time physics simulation over nurbs surfaces while the other couldn't even pull correct ones in batch mode (at 3 times the cost).

The first Mac OS X upgrades were similar, they made your old iMac do things faster.

I don't know how to make devs create non bloated programs, I often think we should give them really old systems to write on. Constraint drives creativity etc etc.