This metric makes no sense. The full arrangement is part of the craft of making music. You probably wouldn’t listen to an isolated bassline of a full album either, is bass objectively worse than other instruments?
First of all, yes, bass - much as I love it - is an objectively less expressive instrument than e.g. a guitar or a violin. That's its function as a part of a rhythm section. Second of all, yes, even isolated bass track can still be called "musical" in the broadest sense of the word and is conceivable to be listened to as is, so it retains its objective musical qualities more than growls.
Isolated growls are also "musical"- almost every sound is, really - but much less so and its expressiveness nears zero.
The problem with this growls vs no growls discussion is that you guys are trying to attach a level of objectivity to personal preference. In the end, everyone just sounds unreasonable and petty.
Well, sorry, but I believe that there is an objective Truth and objective Beauty which don't care about your (or my) opinion and preference and that we are called to try to objectively discern it. Yes, I believe even aesthetics can be objectively measured and are a science of sorts (a soft, "higher" science, of the "liberal arts" sort, like economics, philosophy, theology, not an empirical one).
As for your other complaint
and I do try. I really, really do. Might not seem that way, but I honestly do my best. Sorry.
But okay, I promise I won't discuss growls here anymore. But please, could you all try as well to not fall back into
this particular discussion again? Pretty pretty please?