It's because of social control and hypergamy.
Basically, people want the best that they can get, but life works differently for men and women. This is basically my perspective in my 27 years of living on Earth.
Men are expected to engage with women, to court them into dating, romancing or marrying them. Women, although just as able of doing this, are generally expected to have guys go to them.
Because of this mating dynamic, there are certain strategies that are employed to get the best outcome.
For men, there is generally a quadrant, where one axis is related to going for easy women vs challenging women. The other axis is related to going for a lot of women at once vs focusing on one at a time. Here are the results:
1. Easy women + a lot at a time: basic fuckboi mindset. Get em, fk em, leave em. Rinse and repeat. Generally a follower of hedonistic philosophical mindsets.
2. Challenging + a lot at a time: playboy. Romance for them is about excitement. They get a rush for going for difficult women.
3. Easy woman + one at a time: life on easy mode. Doesn't want to work hard for a woman. No hate on this guy. He'll prob get bored. Then again, so will she lol. Generally into relationships and marriage.
4. Challenging woman + one at a time: wanting the best for marriage. Works hard to be the best. Gets the best. Makes a family with the best. Most woman think of this guy for marriage, without realizing they may not be the woman he's thinking about, which is why they get frustrated when they get hit on by guy number 3.
I'm not gonna get into women, cause I ain't an expert on them. However, knowing this sort explains the taboo.
If a man can guilt trip a woman into lowering her standards, she becomes less challenging. This makes mating easier. This makes life easier. It's a biological strategy. Not acknowledging that its hypocritical means potentially getting a hot woman. Eating their cake while keeping it too.
That's my perspective.