Nah I don't mind it when it's reasonable. But is 0.75% reasonable? That's the % that my current pool has of the total hash power.
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It's inevitable that some pools aren't going to make it because they aren't getting the kind of support they need. You spelled out precisely how things would play... miners leave a pool because it's got too much variance for their liking, which causes the pool to have more variance, which causes more miners to leave, which causes the pool to have more variance, etc.
P2Pool actually has the opposite problem than most other pools. In your "typical" mining pool, the more hash rate the pool has, the smaller the effect of variance on the individual miner. In p2pool, the more hash rate the pool has, the larger the effect of variance on the individual miner. This is because of the nature of the share chain inherent in p2pool mining. For example, as of right now, p2pool has about 3PH/s on it. If you've got an Antminer S3, you can expect it to take over a day to find a single share to get you on the chain for payout.