Here's why it matters.

A better question is, is it sustainable? And the answer seems to be...nope, and it won't last much longer. Most of the pools are shrinking while BTCGuild, Deepbit, and Slush are looking like they are going to be the only winners.

One crazy thing about the bitcoin community is that the 'clever' guy is more common than the 'average' guy. Or you could say, the average guy for the bitcoin community is a clever guy.

It's funny...I'm not at all an expert on academic approaches to ethics and morality, but one of the famous ideas from the field does apply here: Kant's categorical imperative. Basically, 'what if everybody did that?' Generally, a clever guy can say 'well, most people aren't clever so we don't have to worry about that nyah ha ha!' But the bitcoin community doesn't work like that.

What if everybody mined for a while on a small pool, then jumped off before the block was finished? A plague of grasshoppers...

Well, it is working more like this: what if the majority of miners did this? Then the minority of honest miners would gradually leave for bigger pools. When the hoppers come back for the next round, they find a major reduction in the pool's overall hash rate. Some of the hoppers look at the trend in rates and decide sensibly that it's not worth coming back to this particular pool at all next time. It's a death spiral.

The small pools seemed to be doing ok when it was still a few days avg per block. Now that it's about a week or more for a lot of them, they're falling off.

Can they change their payout structure and survive? Maybe...but maybe not. It'll be challenging for a pool that has lost a lot of its average hash rate to get people to come back. How should they do it?