All true. I'm still not sure how you made the leap into "if it has horns I'll cut it down".
Because it's a video game in which devils demons and stuff like that are evil and seek to cause harm. Exceptions may occur, but they are the exception and not the rule, so your prejudices are actually justified. To treat tieflings as if they were just human is actually a problem because they fundamentally are not human the same way elves aren't. You are basically reducing an entire species to cosmetics.
