The reason they say that is because they want to discourage you from doing LL. These are women who are obsessed with height. And they can not for the sake of god accept that they might get cheated by a man that had LL. If you want to do LL, go for it. Noone will call you out for it when you dont tell anyone. Keep it to yourself and play some height obsessed women lol.
Just to give a small overview. There are different aspects women value in a man. From a psychological point of view what matters is:
(1) hypothesized good-gene indicators (e.g., masculinity, sexiness)
(2) hypothesized good investment indicators (e.g., potential income)
(3) good parenting indicators (e.g., desire for home and children)
(4) good partner indicators
If you are short, at least be healthy and work out. If you are smart thats a huge plus. Women know that smart children have it easier in life. They get educated and secure a good job. Being tall doesnt do jack when you are stupid as hell. You will be working some ty minimum wage job carrying weight from A to B like an idiot.
Also work on your personality. Be a good partner, good parent. Dont make it easy and simply say i am short and this is why I fail at life. That is a very easy way to ditch every possible effort to change yourself and simply blame everything on height. Thats actually disgusting. Its like saying why my parents arent rich, now I live a bad life.