Reading music is a valuable skill, but not one (evidently) that aspiring guitarists are inclined to tackle, even now. I know a lot of amateur guitarists, and the only ones who can read music are the ones who learned to do so while learning some other instrument. I read music, but almost never apply this skill to guitar, because it just isn't how the (non-classical) guitar community communicates.

Which isn't anything to be happy about perhaps, but does seem to be the reality of the situation. I'd put reading music in the same category as tabs etc: "You should really learn this, sooner is better than later, if you're serious about guitar". But a lot of people struggle to get off the ground with guitar at all, so I can still see value in something like gTar. Though I do see it as a niche market (musically struggling, iPhone owning technophiles).