I think it should only matter in themed battles. The way y'all are talkin no theme battles should be trap type beats, which is a theme. No theme battles should be just that. They should just be judged on dopeness, mixing, layout, ect.
You're 100% right..
I think one point they're making, is that it can sometimes be hard to choose in a no themed battle. When there is really no criteria/requirements and you have multiple tracks that are dope w/ a good mix, picking the better beat can come down to personal preference. But that the beauty of hip-hop there is no one sound.