The original paper proposes that if the majority of the nodes are honest nodes then the network will be safe from manipulation. If the majority of the nodes are dishonest nodes, an attack is possible.
Don't know about the 39.99% perhaps gentlemen's agreement between Pool operators.
To be fair, I see this as a failing of the other pool operators versus a GHash issue. Earn your piece of the pie, do marketing, drop your fees, increase rewards, have a lottery, pay 10 BTC to the finder of the block like Nakamoto suggested: "Either way, the user who submits the hit that solves the block should get an extra amount off the top, like 10 BTC"....this is meant to be a free market is it not?
IF you "vote with your CPU", clearly other Pool operators need to improve their campaigns to get more "CPU votes."
The problem in this case was clealy demonstrated to be mindless sheep mentality. The same way intelligent people complain about the government inefficiencies but the sheep ruin everything. Other pools have demonstrated to be better performing and yet people flock to something with 0% Fee and 2 extra coins because they think they make more all while bending over and dropping 2-4% orphan rate
