I think sound quality, that is fidelity, is objective, of course. Something either reproduces the original sound accurately or it doesn't. Whether that is desirable is subjective and subject to culture, etc.
While I like hi fidelity recordings, I also really like early punk, 80's hardcore, and 90's indie rock. None of it is terribly hi-fi, but I don't think it loses anything, in fact I think it gains value from that.
On the other hand, getting used to bad reproduction is a problem, I suppose, but if that's that case, anyone raised in the era of small speaker radios, LPs played on mono all-in-one record players, etc should have terrible hearing and not be able to tell the difference between a CD and a micro cassette recorded at slow speed!
Now, getting a mix to be balanced, and sound good, etc, is no easy feat. Getting it balanced, without 'errors' and technically even is pretty easy, but getting it to sound, artistically and aesthetically consistent with the vision the artist is trying to put forth is the hard part. The best engineer, from a technical perspective, often doesn't create the best final product because he simply doesn't 'get it.' You mention in your first post the importance of being aware of the genre, and I think that is key, but I think there's a step beyond familiarizing yourself with the genre and 'getting it.' I can familiarize myself with hiphop, but I don't 'get it' and I don't think I could do an artist justice, no matter how well I eq'd, compressed, etc. Maybe the thing that mix needs is tons of distortion, or some crazy flanger. I'd have no idea.
Now, finally listening to your mix!
First impressions are that the drum sounds are too ambient, and a little soft for this track. The kick in particular disappears when the instruments come in. Toms are kinda muted, a little like a jazz drummer playing with a rock band. Snare seems kinda thin, could use more body, and doesn't seem to have any sustain to it.
The guitars seems a little thin to me, edgy and a little harsh in the upper mids, but kinda anemic.
Bass guitar is pretty good, could maybe use a touch of distortion or something to add some articulation. Mostly it's just masking the kick too much to my ears.
The vocals are a little on top, and a hair syballant here and there. Maybe a bit more compression, and some de-esser. The reverb is a little too much for this type of track, I think, or maybe just not blended in quite low enough. Not sure, my first impression was 'whoa, reverb!' :-)
As far as building tension, I think your mix has the same problem as most, it doesn't have a real payoff, sort of loses momentum after the bridge.
Tonality wise, your mix doesn't seem off balance, there's good lowend, good mids, good treble, just stylistically it doesn't really work with the track.
Hope that doesn't sound overly negative, I'm trying to give my honest impression. My mix suffered from some serious tonality issues (my own fault for trying to mix in a new room, without referencing, using some new outboard for the first time...) Thanks for posting!