I'll have to take exception to this sentiment. When people say 'they should just make better movies', it implies two things:
1. That there is some simplicity to making good movies that people in the industry with their years of experience somehow miss. If it's really so simple, why don't these armchair critics make movies themselves? Trev nailed it - it's far easier to criticise work than to make it yourself.
2. That people who are making movies are not trying to make them good or aren't putting in effort. With multimilliondollar budgets at stake, Paramount would be trying to make the movie as good as they could. Cast and crew on Michael Bay's movies have consistently described him as hard-working.
The impression I get of Michael Bay is that he doesn't care about critical acclaim. He doesn't make Oscar bait. As far as he's concerned, moviegoing audiences are his critics. For some reason or other, it's popular to hate on his work, which is why he keeps getting Razzie nominations.
Edit: sorry if the post came across as harsh, but I find that "they should make better movies" statement irksome.