One thing about classical guitar, because it's basically a solo instrument, outside of lesson time with a teacher, its pursuit is basically a solo effort. Something that can be difficult in the long run for social creatures such as the members of the Homo Sapiens Sapiens species. That's one reason why I also pursue playing -- I guess you'd call it "folk" or "pop," I dunno. I just call them "songs that I like," irrespective of genre. The only common thread being that the music is sung with chord-based accompaniment on guitar.
It's fun being able to "jam" with guitarists and other musicians. I just did so with my nephew a few days ago, who plays clawhammer-style banjo (EDIT: Like I told him, "It's a dirty job, but somebody's gotta do it."
), and we had a gas. Not to mention there's a lot of songs out there that I like, and I've even "written" one or two ditties.
My practice probably involves, at most, 20 percent songs and 80 percent classical. And I have long stretches where I practice classical exclusively. After which, going back to the songs, I've always improved playing them anyway. I mean, what better practice for Travis picking than working on Guiliani's arpeggio studies?
As far as The Big Question goes, it's obvious that human beings were designed with built-in emotional responses to music. Which means to me that music needs no utilitarian justification beyond itself. It's not a means to an end, it's an end in itself.
And as far as the edification of the player goes, what more fun can there be in the world than playing Bach that doesn't require changing the sheets afterwards?...
Attitude is more important than the past, than education, than money, than circumstances, than what people do or say. It is more important than appearance, giftedness, or skill. -W.C. Fields