I don't think that is true. I think Hoyer saw a manager in his dugout who was not capable of getting the team to where he wanted it to go and one came available.
Hoyer's fatal flaw is picking guys like Happ, Hoerner, and Swanson to build a team around. They are good players, but not difference-makers. If you add up the money spent on them it will get you to a pretty high payroll, but a mediocre team. Also, and I'm not absolving anyone here, the injuries have hurt quite a bit, especially in the pen.
That said, Hoyer needs to go, but he's a mini-Tommy Boy.