I agree with you on some points. A girl shouldn’t be turned down sight unseen. However, to say that weight shouldn’t be a factor at all is ridiculous. A man must find his wife attractive. If a guy doesn’t think the girl is good-looking, he shouldn’t marry her.
Something once happened to a friend of mine from Yeshiva. He asked our Rosh Yeshiva for advice. he was dating a girl. The conversation was great, they were on the same page hashkafically, etc. He had one problem: he didn’t think she was good looking at all. As he told the Rosh Yeshiva, “I could probably talk to her on the phone for hours. Even in person, once the conversation gets going, it’s great. I just don’t like the way she looks!” The Rosh Yeshiva told him to end the shidduch. My friend asked, “Since when do we put such an emphasis on looks?” The Rosh Yeshiva told him that you must be attracted to your wife, or the marriage will never work.