Preamble: I do not think that large corporations are inherently bad.

This seems to be a good thing. When companies grow large enough to change daily life for a significant portion of people, they grow large enough for monopolistic abuse -- even when they are not strictly a monopoly. Having some oversight into their business practices helps provide some checks and balances to encourage them to play fair. It's not perfect, but this is one way that government tries to provide for the people by preventing capitalism from taking things too far.