One could argue that Warren Buffet should pay higher taxes. And he would agree! But unless you find capitalism itself unethical there is nothing wrong or underhanded with searching for undervalued firms and investing in them.
My biggest complaint is that that instead of paying higher taxes Warren Buffet could maybe not jawbone Congress into bailing out AIG. AIG should have gone bankrupt and Goldman Sachs (and their other counterparties) should have borne that pain, and possibly gone bankrupt themselves. Instead Warren Buffet refuses to come to the rescue of AIG, comes to the rescue of GS, and then tells Congress that the economy will freeze up if AIG and other banks aren't bailed out. That is not efficient allocation, that's crony capitalism.
What is a problem is that congressional representatives are enormously influenced by donations to political campaigns. Even if they lose a reelection there's a whole industry in place to put them into cushy jobs if they've followed their party line. And the party line is to do what the campaign donors want, not necessarily what the constituents want. That is a problem.
(Those guys at least built something. Why does no one complain about America’s grandpa Warren Buffett. He just shuffled around money, plays with warrants and options (while telling others not to) and makes a couple hundred million by going to Congress and talking his book. )