The cost of running a pool does increase the more miners you have, as you need more server resource and bandwidth, but it gets more efficient the bigger you get so 2% fees is quite profitable I suspect. Its a free market so miners can direct their hash where they like, perhaps they figure they get a lower orphan rate which compensates for the fee. I moved my pool to its own server with a direct Internet connection when I made it public, hopefully reducing the orphan rate, but then the network hash rate has gone up so much since it hasnt found any blocks so I can't compare to see if there is a difference 
Where are all these orphans coming from? It's becoming harder to believe that it's entirely due to the 1 minute block times .. maybe that combined with the incredible mining speed increases we have now changes a few things...?
Edit:
Quote from: Tacotime
To address the orphan issue, it's recommended that you directly connect your daemons to the other major MRO pools, mro.extremepool.org and moneropool.com. You should correspond to those admins so that their nodes are directly connected to you with "--add-priority-node arg", and possibly remove unrelated nodes, so that you can sync faster with these other large pools.
P2P backend code seems poorly optimized and takes a long time to sync as well, coupled with the heavy hashing algo makes orphans inordinately high compared to other networks.
Looks like they're already on it! only a matter of time now.
