I'm more so speaking about the "judgments" that people place upon horses because of their breed.
this part I agree with, for the most part. Every horse should be evaluated as an individual. Many horses, if given the chance, would excel in a disapline for which they were not bred. Think snow man. Or the many other exceptions to the rule.
That said, it makes no sense to go looking for say, a cutting or cow horse prospect, and instead of looking for a stock horse with those bloodlines, you go waste a bunch of your own and the sellers time, looking at thoroughbreds, Arabians, shorter warmbloods and some draft crosses. Might one of those work for you? Sure. If you find one with the right temperament, build and inclination, then invest a few thousand into training it. The fact is, you are going to invest thousands into the training regardless, and the odds of success are astronomically higher if you buy a prospect that is from proven stock. If you have the time, desire and funds to give another, potentially ill suited horse a chance, great. But for the most part, you do what you can to increase your odds of success. I am not going to invest months of conditioning in a freisian, with the hope that it might make an endurance horse. No, I'm going to go buy an arab, or other proven breed, ideally out of successful parents. If I had a freisian I might try it for fun, but I certainly would not go buy a carriage horse for long distance riding, or a dressage horse for cattle work, or a 14hh cutting horse as my next show jumper.
People holding onto silly, unproven prejudices about a breed(or for that matter a gender, height, color) is unfortunate. Hating something is never good, and criticizing others for liking something different is not good either. No one should be bullied or put down for choosing to ride a horse of a different breed, height, color, bloodline or gender.
I have opinions, and I think everyone is entitled to their own. I don't like most quarter horses. Either I find them boring, or they are trying to kill me. I know I have only been around a tiny fraction of the qh's out there, so my opinion is likely unfairly biased. But I still would not choose to go out and buy one. I love thoroughbreds, but I think most of them are suicidal, so I would not own one. Personal preference is one thing. Looking down on people who don't agree is another entirely.