Yes, I would love to be 25 again . . who over 40 doesn't wish that sometimes? Without that sentiment, there would be much less cosmetic surgery, skin treatments, fewer older folks in workout classes, fewer 50-somethings trying to dress and act like 20/30-somethings. But, its not going to happen and I don't let such regrets dominate my thinking (I do still like much-younger gf's however . . something that is increasingly a thing of the past too).
I used the "youth" example (see my previous post, "You Haven't Noticed?") to compare to the "breast freedom" issue: Young people in a club don't want older folk around . . . . and people really don't want to see older/unfit bodies baring skin (see my thread "THIS!!" above). People in a decent neighborhood don't want a wreck of a car sitting out on their street . . . they don't want a neighbor's home to have peeling paint and otherwise looking unkept . . . . they don't want to be around people with bad body hygiene . . . they don't want "undesirables" around when they're trying to "pair up" . . . and they don't want to see "ugly" people displaying more skin than absolutel;y necessary.
I've not been to a nudist resort, but from everything I've read and seen, a sizeable mojority of the people in that lifestyle are not very attractive. I think this is because, 1) Most people don't look very good naked, and 2) the ones who want people to look at them are not very attractive and don't get much positive attention for their physical appearance. Conversely, good-looking people (especially women) already get more attention than they want and they don't want to encourage more by baring skin.
A perfect example is Mardi Gras: The place is filled with older, overweight, drunk women with boob implants who flash anyone within range. Really, "flash" isn't accurate, as they stand there holding their tops up and rotate around for everyone to see. Also, these are usually the women that will flash their bottoms as well as their tops. There are some younger, naturally-built and good-looking girls, but if they flash at all its very quick, and they are much less likely to pull their pants down.
Trim, fit and good-looking women are already getting plenty of attention (clothed!) and they don't want more. Women that don't fit that description don't get attention and they want it (the boob implants are shown because the women didn't get attention to their chest when they were small --- naturally busty women don't tend to want the same attention cause they always got it).
Now, older/unattractive people can stiil be very nice people and have other great qualities, and no one should go out of their way to mistreat them. But neither should they blight the environment by putting their undesirable flesh out there for public consumption.