Well, I'm coming back to the "they work with other pools". 

I've donated to p2pool plenty - I left the author donation on, and I even sent BTC - but nothing has been done in ages.  p2pool really is becoming a still-birth. It's not 2012, people aren't mining with GPUs any more.
 
I know I'm only a low-scale miner (30GH, soon 50GH), but I'm not using p2pool because it doesn't work with my hardware, even when I mine to p2pool through a proxy.  OK, it's only 30GH, but if I'm giving up on the pool, what are the chances of new users going to the bother of setting up a machine, only to find it doesn't work?  Nil.

p2pool's continued EXISTENCE relies on it being able to cope with the current and future ASIC miners, no matter what retarded firmware on them does.