Any director that has a beautiful woman in his film will want to maximize her exposure (not expose her), while I don't think Megan Fox or Liv Tyler or a few other Bay girls are hot, he does show them off in his films like most other directors also. For a girl as vacant as Megan Fox, she should feel blessed that she even gets to do that. She can't act so all she has going for her is the dirty ***** pout and parading around.
I never saw Liv Tyler as eye candy but then that's just me. Kate Beckinsale is a good actress and I don't feel Pearl Harbor objectified her, it was just a weak script with the whole love triangle BS. Put Kate in any scene and people will think she is being objectified, she's a beautiful woman on screen.
I don't doubt that there may have been friction, I'm sure that is the case on a lot of sets, not just with Bay. Is he a tool, maybe, that isn't really in question. I enjoy his films (even though the last handful have been less than great) and give him credit where credit is due. He made Megan Fox, she will eventually just fall by the wayside.
So love him/hate him, love her/hate her, he's going to be around longer. People really have to get tired of her at some point. I just can't believe it's taken this long.