"Everyone knows weddings belong to the bride!! I mean, have you ever heard of the man wanting to have opinions? This is crazy!"
That is silly. Lots of guys have opinions on stuff in their weddings. Few of them are as invested as the bride in a lot of the details, so they often defer to her opinion. Many of them, however, have strong feelings and advocate for them. Personally, I feel wedding planning can be a good indication on how a couple will manage disagreement in the marriage. Some of the stuff is trivial like napkin color or the flavor of the cake filling, but some of it has deep emotional significance - religion, family relationships, etc.
Our general rule from the wedding on up to yard work, housekeeping, etc is
"Opinions go with responsibility". Neither of us gets to dictate or nitpick while the other works. Things we both have opinions on, are things we take joint responsibility for carrying out.
So if the groom is participating in food tastings, bookings, researching/meeting with vendors, planning and carrying out all the nitpicky detail work - then yes he gets input into the decision. If he expects her to do all the work and then second-guesses her choices, then he is being a jerk.
But that doesn't sound like what you overheard. It sounds like that groom was participating but not being heard. Not a good dynamic.