Those are valid points, sure, but at some point physical attraction does play a factor in marriage. It shouldn't be the most important factor, hell, probably not even top-5 (off the top of my head emotional stability, similar goals, economic stability, shared interest, family background, all in no particular order), but it does need to exist. Contrary to what some people think, there are any number of women out there that are good people and who can make excellent spouses and parents. Perhaps this is cynical of me, but it seems unlikely that a person who has been that weight for a prolonged period of time will change it i -- furthermore, she could just have genetics that predispose her to being overweight. No matter what she might do to remain fit, she could always be the type to be heavy.
Just because you don't want to marry an overweight woman doesn't mean you want to date some vapid, anorexic sorority girl