Miners have invested millions in bitcoin, do you really think they're so stupid to destroy it?

If you are opposed to the miners, you should think twice about your opinions, because miners only want 1 thing.    

Miners want bitcoin to be successful, because otherwise they lose millions.

Investors can just sell their bitcoin and they'll be fine, even if they invested millions into bitcoin. Miners can't sell their hardware and recover their investment. So miners will be the one who suffer most when bitcoin crashes.   
They will do everything in their power to keep bitcoin healthy.