Of course these words mean 'something', its just that one has to work hard to ferret out the meaning being applied by each user. No difference between how people apply modifiers to audio or anything else.
There's a big difference. If I put my hand on top of an amp and say, "this amp is warm," you know something--you know its temperature exceeds room temperature, but is not so hot as to be untouchable. But if I describe the sound of that amp as "warm," you really can't be sure at all what I mean. In that case, "warm" isn't anchored to any scale that you can use to narrow down my meaning.
An interesting experiment would be to ask listeners to compare two components (blind, so they aren't influenced by prior information) and decide which one sounds warmer. Then see whether most people agree. Until somebody does that (and no one has, to my knowledge), there's no real evidence that "warm" means anything like the same thing to people.