I believe the problem lies in many areas.
More hashing power = more blocks solved = more money. Everyone is mining for money
The pools that have decent hashing power where you can still make money but it averages out longer
have shitty fees so people don't want to mine there.
The ones that keep mining there do it for various reasons from loyalty to laziness to explore different pool options.
The pools that have what I consider excellent terms have no hashing power yet and you might as well be solo mining.
P2Ppools are good but might as well solo mining if you don't have much hashing power and have higher than 30 ms latency to the pool.
Ghash took it to the next level by selling could mining and exchanging currencies as well as multipool profit.
So any new pools or existing pools need to step their game up I believe.
Some pools haven't updated their site since they opened as a pool years ago.
When you make creative criticisms people tell you to go start your own pool.
It's a circle jerk imnsho