The hatred for Santa Cruz bikes tends usually comes from the people who want one but can’t have one.
Santa Cruz was once a rare, pioneering and daring brand who tried things and were rightly placed into the ‘aspirational’ category, where you had to know something about bikes to get one and build it up right for it to be any good. They have now built themselves past that into mainstream success (good for them). However a few who buy them still brandish that ownership as something special, unique even, but its not, its buying a bike from a shop, one of hundreds if not thousands the same, no different to a top end trek or specialized.
Any hatred is of those few, and may have rubbed off onto the bikes as its often those few who post them on the internet 😆