I've always thought Warren Buffett's early partnership model was far more intelligent (for the LP at least): he received nothing if he delivered less than a 6% per year return, which he justified because it was a reasonable rate an investor could achieve at low risk, and 25% of all profits above and beyond that 6%. He only ever earned anything if he was generating returns for his clients.

I've never understood what justification GPs use to charge 2% management fees. Imagine you could just sit around and earn 2% on other peoples' money, year in and year out! If your fund is big enough, actually earning returns on your LP's invested dollars is just a way to get richer, but not necessary to get rich.