There are various hate forums online, ranging from racist communities, to the now defunct "fatpeoplehate" subreddit. I've seen people use the existence of these forums to lessen the severity of height prejudice. "If height discrimination is so prevalent, name one popular hate forum about short people."
The reason various hate groups exist, is because if these people shared their views outside of their domain, they would be massively downvoted or banned. This is why they have to create their own space to talk freely. On the other hand, you can openly talk like this about height. You can even be rude in person, so there is no need to hide in a corner if you want to discriminate based on stature.
This is also relevant when it comes to those who say, "You can find hate against anyone online, so all these examples of height discrimination is no big deal." What matters is whether or not that hatred is mainstream. For example, you can find people body shaming women online, but is it politically correct? Nope.
Anyway, this whole thing is just another form of the fallacy of relative privation. People try to downplay height prejudice to make it seem more okay.
