I know I sometimes reflect too much on the past, but shortly after PQs first came out I can remember listening to the left coasters complain that the 500 cache limit per query was not enough and I was always bragging how I could get all Maine caches in one PQ. After a year or two I started to see their dilemma. Even now if there was a 2500 cache limit, it'd still take 3 PQs to get all Maine caches.
If the pace keeps up, we'll be saying we'd be happy if there was a 25,000 cache limit per PQ!
Unfortunately upping the number of caches per PQ would require much more server power than gc.com could afford without charging more (or charging everyone) to play.