GAW- while dating, they are off limits. everyone else hypersexualized everything in society, and if youre familiar with bochurim today, you would understand and know how the slightest trigger is still a trigger. it also diplays a level of heimishkeit that certain big people deem unappropriate at this point in a relationship.
With regard to your first point, i disagree. obviously i dont mean have kids and make them chareidim. i mean that the goal of our existence is to be mikadesh shem shomayim. you are digressing from the centrasl point of our argument which is whether or not factors that can cloud logical judgment should be introduced into a decision that is nearly entirely logical. for some reason you think that two people should develop taivos that preclude their ability to make an unbiased decision. you alone agree that a relationship with ones WIFE should be that of love etc., not with your date.