Not saying that beautiful characters are bad, but semi naked characters with unrealistic beauty which both have nothing to do with the game at all is terrible, very terriole.
You did talk about unrealistic beauty as well.
And as for why, the answer is simple. For every person like you that strongly dislikes it, there are probably 9 gamers that prefer it this way and buy games that do it. Which of course results in about 9 out of 10 games including it. (numbers made up to illustrate point). There really isn't anything wrong with that. If art had to appeal to everyone, there would be no art. You are just unfortunate that your taste is in the minority so there is less content matching your preferences.