Not nearly enough power or impact for that. The masses of miners who could roll back will not care for their plight and even billions stolen is worth less to the community and miners than making sure all transactions go through. For example; imagine what else is on that block chain they'd have to also kill? How many times exchanges been hacked and no re-dos? How could bitcoin keep it's status as super-solid if they allowed such things and it's only that status which gives it value? Totally untenable for bitcoin.