I've been told "the network" sets the difficulty level such that there will be one new block mined every ten minutes.
I imagine the rich would instead prefer to keep difficulty as high as possible to prevent other people winning their 50 BTC and causing inflation, whereas the poor would prefer as low a difficulty as possible in order to get a greater share of the BTC available.
(By rich and poor, I mean only according to how many BTC someone has.)
What's the force saying "No, forget your petty self-interest and set the difficulty to 10 minutes."?