I don't think you're using "accountable" in the same way. A corporation is accountable to its owners in its quest to make more and more money. If making more and more money means doing unethical (but legal) things, many owners will have no problem with that. That's not a good situation.

Corporations are only accountable if they fail to make money. Unless they're too big to fail, in which case they're accountable to no one.

It's all well and good to pick a blatant example of a politician doing evil and getting away with it; on the flip side I see politicians at the local level losing re-election for doing things their constituents don't like. In any event, I'd much prefer democratic accountability over corporate accountability when it comes to entities who have the ability to take away my freedom or deprive me of life.