Although I don't typically read novels where the romance is central to the plot, one of the few times I was watching a romantic comedy and enjoying it got ruined for exactly that reason. The movie was all about "be yourself instead of fake, it's more attractive!" and then the male character had to give himself a total (and unrealistic) makeover to attract the female character.
On reflection, however, I have decided that this is actually a more realistic lesson to teach people trying to actually date - sometimes, if you want a certain kind of partner (or even a certain specific person as a partner,) you need to make changes in yourself to get that kind of partner, because without those changes, you aren't an acceptable partner to some people.
Yeah, I do think there's a certain realism to that. Immediately I thought of, immature slacker who doesn't want to grow up, who finally realizes he needs to clean up his act, take responsibility, get a job, etc.. I mean, as long as he isn't hurting anyone else or mooching off them, I guess he can be a happy slacker his whole life if he wants; but probably, the go-getting, up-by-her-bootstraps law student is not really going to be interested in him, you know?
Sometimes falling for someone can inspire one to change for the better, like living healthier or being more responsible. In fact, isn't there a recent romantic movie (or two) with the line, "You make me want to be a better person"? But, it has to be a deep change, and not just an act one is putting on, or it won't last. I feel like most romances (book or movie) that attempt to tackle this subject do so only in a shallow way.