D&D 3E/3.5 - Why did they nerf the "sleep" spell in 3.5?

I don't see anything wrong with empowering this spell. At best it rivaled higher level disabling spells like Hold Monster. At best.

I disagree. My high level characters use low level spells alot. Feather Fall, Magic Missile, Charm Person, Grease, Comprehend Languages, and True Strike all see alot of use (among others). Low Level spells tend to be designed with alot of utility in mind. This doesn't mean that they are overpowered. Why use a high level spell to accomplish what a low level spell can do?

One should not use Meteor Swarm to heat his afternoon tea, for example.