I'm seeing a popular trend where people try to explain/justify heightism by claiming it's just a part of attractiveness, so deal with it.
Heightism is about as linked to looks as racism is. Here's a video where Malcolm X talked about, and I quote, "Who taught you to hate the texture of your hair? Who taught you to hate
the color of your skin to such extent that you bleach to get like the
white man? Who taught you to hate the shape of your nose and the shape
of your lips?" I've seen racists mocking Asian people's eyes and bone structure. There are statistics showing how Asian men and black women do worse in dating. Is this all "just about looks?" Perhaps certain races do worse in various aspects of life simply because they're uglier on average.
Technically, it's that first impression when one sees a person that triggers racist thoughts, but it's not just about seeing. It's the underlying stereotypes and portrayals. Things like "short man syndrome" or "Napoleon Complex" are not at all about attractiveness, that's outright discrimination. And yes, things like this exist even without slavery or lynching, so hopefully nobody tries to point that out because I mentioned race. I'm just showing how attractiveness has always played a role in societal prejudice.
Why is it "tall, dark, and handsome" if tallness is supposed to be part of attractiveness? We don't say "chiseled, dark, and handsome" because people are supposed to know a handsome man has a chiseled jawline/body. I've seen women saying they find short men attractive, but they "can't" go out with these guys because people would mock them. Tallness is more like a status symbol, such as having a lot of money or being a certain race in a racist society. Going out with a short man is like going out with the race society is currently hating. On this note, I've seen many girls claim they they never found Asian men attractive until they watched too much Japanese or Korea media. Now some even prefer Asian men. This is one thing I will admit is similar about height and looks, although again, it's more about social status, stereotypes, and portrayals than actual features.
Height also plays a unique role in employment and leadership. Who would most men rather be seen dating, a 5'3 or 6'3 woman? Most would probably find the former more appealing, but the latter would actually do better in the workplace. This is similar to how men are more intimidating than women, but the difference is that society does not accept this as an excuse for inequality (more on height and employment here).
Looks are subjective, but height is not. There have been times when my friends found someone attractive, but I thought they were not. Same the other way around. A cafe can't put up a sign saying "not hiring anyone less than 6 out of 10 on the attractiveness scale." What would that definitively entail? Meanwhile, this practice actually exists when it comes to height. Here's an article from China: "A female kitchen hand had to measure at least four feet nine inches; a
waitress had to be a minimum of five feet; and the pretty hosts who
greeted guests at the door needed to be a lofty five feet five" (source). In the United States, men under 5'3 and women under 4'11 are outright labeled with "idiopathic short stature." I don't see how society could agree on a uniform "idiopathic ugliness." The final example for this is how the East differs from the West when it comes to Asian women: . As a side note, from the first page, someone outright mentions the way feminism made beauty standards more lax for women. Funny, because I thought this shit was all "hardwired" (that's how society talks about men's standards, not me).
When it comes to everyday terms, people also do not take kindly to mockery of other genetic traits (breast size, baldness, etc.), at least in big public gatherings. Heightism, whether in private or not, is always just a prank. The only ones who come close to dealing with something similar are men with small dicks or fat people, but the first is not easily noticeable in public, and the latter isn't genetic. Perhaps on a smaller scale, ginger men come closest, I wouldn't know. Not too many Asian, black, or brown ginger men though, but a lot of short men of all races. I also rarely see much anger and hatred towards unattractive traits. It's often simply mockery, which is still heinous no doubt, but the way people talk about a short boss or officer makes it seem like they don't simply dislike the physical trait, they hate the trait and human being behind that trait. Can you find me a thread about big noses or flat chests similar to this one, which is about beating up "Napoleon Complex short men?"
All in all, this is just another attempt by society to justify its bigotry. If it's not this, it's something else. Same old evo-pysch crap, or short men have shit personalities, whatever. Let's say a study came out proving a certain race was universally deemed uglier by society. Would that justify discrimination against that one group? Hopefully that's a rhetorical question.