Why does everyone say it's "her" wedding. Isn't it both their wedding? What about rules of equality where these decisions should be shared. Again, wedding are silly. If someone remembers, ten years from now, that the OP was wearing the wrong shoes, then SHE has the problem, not the OP!
Well, that's a fair question. The clarification is that it is their marriage; HER wedding. Most men don't grow up fantasizing about their wedding ceremony and most girls do. Most men don't plan the wedding for years and have scrap books with ideas for the wedding and reception. Most women, even single women that aren't dating anyone, have their wedding planned out. There are clearly obvious exceptions.
Most women will remember everything that happens on their wedding day and during the ceremony and reception.
The key is to ask happily married men these questions and just take their advice and don't argue. If you're looking for logic, you've already lost the game
The OP said the groom picked the groomsmen's outfits ... and maybe he did. The OP says he asked them and thinks they don't mind because that's what they said ... and maybe they don't.
I think the odds are in most instances she will have picked the outfits, and would be too horrified that someone would ask such a question to give an honest answer; and gave in. Ten years from now the bride will be showing pictures to someone and the groom will have to hear about "your friend that couldn't just wear the same shoes as everyone else." Even if the PAs are more correct, that's not how women feel. <- notice I did not say "think."
Regardless of whether this bride and groom know it or not; it's rude and self-absorbed to dress uniquely as part of a wedding party.
Usually bridesmaids buy their dresses and matching heels. It's only the men that are "out of it" enough to have these types of issues. Thus reinforcing that the whole occasion matters MOST to the Bride, her family, and her girlfriends.
Now, if the OP suggested that the entire party wear PAs; that might be a good conversation about which is more correct - the PAs or the square toed monstrosity.
As for the double standards of marriage ceremonies; you might as well ask about the groom's virginity ... It's always been a double standard and it probably will always be one.