Fret not! I listened to the same when I was in middle- and high-school, and eventually reached the conclusion that what ultimately bound the music under the "alternative" label together was nothing more than pseudo-rebellious Gen-X marketing aesthetics, rather than some actual stylistic association. It was mostly all just "rock" - as a genre, not a style - in a different outfit, at the end of the day.
Of course "alternatives" to rock still exist, but that's an always-moving target; the "rock" of today is - funny enough, considering your username - the countervailing, ever-expanding umbrella that amalgamates all that is no longer "alternative," the very thing which the new and non-traditional forms innately oppose themselves to. The "alternative" of today is, for one, not called that anymore, and two, not to be found by any means in the same channels through which it once flowed.
Perhaps the broad strokes of society just aren't ready for it? Perhaps they won't be until it's "over," moved on to something else - perpetually ahead of the curve. But it's out there, if you know where to look and actually do so. Perhaps this is all tangential, since ultimately your point here is about radio, but I think the general consensus is that radio is more or less a dead medium for anything fresh and less-than-commercialized (not that I think it will necessarily stay that way forever - you could look at the vinyl boom for a potential analogy).
Anyway, I like your writing; I read your intro post and you're definitely the kind of person I could stand to see a lot more from on Steemit, so I've got you followed. I write a lot about music of all kinds in my column The Harmonic Series, and I have a hunch you might enjoy it. Here's a link to my 2017 Top 10 Albums list, check it out if that sounds interesting to you.
In a lot of ways, I agree completely how it was more or less a rebranding of the Gen X cultural scene. In a lot of ways, it's even more that scene that I miss than the music itself, if I'm being honest. Those moments were MTV was still relevant and hip and showed it with subversive and weird programming like Beavis and Butthead and Wonder Showzen. In a weird way, these countercultural ideas and concepts have been accepted into the culture at large and further diluted to the point where they're becoming more common and the norm in creative endeavors, which is both somewhat uplifting but also feels like a loss as it seems as if the uniqueness that had pervaded it is now gone.
However, like you've said, there still is a prevailing sense of that creativity to be found in lesser channels. I haven't gotten to dig as deep or experiment as much in recent years as I had a bit ago, mostly do to time constraints. However, it is exciting to always learn more about what's out there. I can agree that radio is dead as far as being a medium that moves the artistic form of music forward. The dominance of big groups like Clear Channel buying out station after station has helped to make sure that it's pretty well safe, cookie cutter slop. Problem being that when you're driving a clunker that keeps shorting most of its electronics out, radio tends to be one of your best bets for entertainment on the road.
I gave your article a read and an upvote. I'm sorry into it, and you seem to know your stuff pretty damn well so I'll be following. I appreciate your vote and liking the article here. I'll be following you during my stay here since I'm always down to discover something new in the arts.