Because if you don't like the idea you don't have to by the security.

And, as it happens, so many people own equities passively (through a managed mutual fund, or an index fund, retirement account and the like) and ownership of a company is so diffuse, these provisions have little impact in practice except against another large entity.

I'm not defending the practice -- I think it is a bad management practice myself and don't buy stocks with such provisions -- I'm simply responding to your comment.