Alot of us do not try and achieve the gambling man orgasm while mining for bitcoins, alot of us have legit reasons for running their miners as a business with realistic daily/weekly and monthly income projections. It would be a self destructive decision for alot of users on a big pool to move into solo mining.
I'm sorry, but IMHO anyone who has invested anything into dedicated mining hardware, since the beginning of this month, "even" when he is mining pooled, is a much worse gambler than I am. There is real money at stake. I, in contrast, just don't switch my PC off at night as I would normally do and that's all. The "business" of recent rig buyers runs on the assumption that we won't reach 10.000.000 difficulty anytime soon (which won't even pay electricity for many and might be on the horizon within weeks) and that the current XXX/BTC rates aren't moon prices. Pooled mining doesn't hedge this risk. There is no market of considerable size for the exchange of real goods or services for Bitcoins. There is just one huge speculation bubble with thousands of people hoarding them in the hope to get rich and who might dump them any time, if they get cold feet. There is no necessary correlation between difficulty and exchange rate. A too high difficulty might also make many people loose interest and motivate to move on and cash in. I don't want to hold Bitcoins on the day when hoards of miners become scared when the long-term uptrend breaks on high volume one day (the recent break was just a short-term trend). We might very well see cent/BTC territory again, and if you ask me, that wouldn't even be a bad thing for Bitcoin as a currency. A couple of weeks ago it was still hot to tell friends of Bitcoin and they could all earn their share with a little effort. Even at the current difficulty this isn't true anymore and many couldn't justifiably care less for the returns you get with pooled mining ATM.
Pooled mining at the current difficulty is only "worth" the effort, if you leverage the current profit by buying extensive amounts of mining gear. This leverage in itself is very, very risky. Even the aftermarket value of the latter is severely threatened by a scenario when mining suddenly becomes unprofitable for many. Because of that I see people, who undertake pooled mining on a business-scale (anything else doesn't pay enough on a pool), as the real gamblers in this game. I couldn't be farther away from that with my solo mining HD5870.