"It's not about height, it's because most short guys are insecure about it."

People love to pretend that it's a short guy's personality which holds him back in life, like this: "Get the fuck over it man, seriously. You get treated poorly because you're annoyingly whiny. Your insecurities about being short cause you to blame every issue you have as being because of your height. Great people don't sit around and complain about the hand they were dealt, they move on and make the best of it."

I found some good comments about this here.

• "Change short to gay. Now see if that statement sticks."
• "Seriously, I have never met a whiny short guy in real life. If anything, it seems we try to go out of our way expressing anything close to feelings about our height."
• "Okay, for the sake of argument, let's assume that short guys more insecure than taller guys on average. Why? Why would shorter guys be more insecure? Are short girls equally insecure? Somehow, they never seem to ask these questions. They throw out the confidence line as if that's all there is to it."
• "This is such a key point to be made. Society treats shortness in males as a defect, so it shouldn't be a surprise that short men tend to be insecure about it. I wish others would at least acknowledge this. That doesn't mean we shouldn't do everything we can to overcome it or let it make us miserable people, but at least give us the respect to recognize that these self-esteem issues aren't coming from nowhere."
• "Shorter guys can't win really. It's like people just expect you to let them make comments about your height, god forbid you try and defend yourself, or you've got a napoleon complex and a chip on your shoulder."

Whether a short guy is insecure or not, he's not allowed to even discuss these issues, lest he be negatively labeled. When a short guy treats others poorly, people don't say it's okay if/when the target is insecure, they say the short guy is an asshole. But when it's the other way around, a short man isn't allowed to defend himself or else he's insecure or has a complex.

It's also funny how when women are insecure about their bodies, we're told to back off lest we make their mental state worse. But with men, it seems like the message is that it's okay to to keep pushing a guy if he is insecure. Thus it's basically never okay for men to be insecure (but also be sure to not always act like a tough guy, or else it's toxic masculinity).

This is all essentially the just world fallacy. If you’re treated poorly, then the fault somehow lies with you, and the person who's actually prejudiced gets away scot-free.