Most men fear rejection and struggle with finding a mate, so if they can pay to remove rejection, even if they know that the chance of genuine reciprocation is low, most men are willing to pay that price. The term "simp" originated in the 1920s, and is used to describe men who give presence and praise to women with the expectation of receiving some sort of sexual or emotional ratification, but they receive none of it because they're pliable.