Looks are extremely important in shidduchim.
I think what people mean when they say people are too picky about looks is that people decided beforehand that they need a certain type of look (example: blond, size 2) and won’t go out with people who don’t fit that look. A lot of boys would have no problem being attracted to a size 8 if they wouldn’t know beforehand what the size was. They also care about too much about what other people will say about their spouse’s looks. They not only want someone who they are attracted to, but they want everyone else to say they got an attractive spouse. Also, mothers of boys also want to love the way their daughter in law looks. It’s not enough for them that their son is attracted to the girl. So they have to check out the girl beforehand and there’s another reason why the shidduch might get nixed before it gets off the ground.