Everything. Management is terrible and will talk negatively behind your back, no communication (at least nothing consistent or truly informative) within AND between departments, employee morale is non-existent, HR is a joke, the company makes you feel like you don't matter, the benefits are horrible, no room to advance or to be taken seriously, honestly... the list goes on.
Listen, I don't doubt some people have a decent experience, but the overwhelming majority will agree this company requires some serious improvements.