The problem is that I unwittingly lied in one of the comment conversations. I said "there were stories I wanted to read and no one else was writing them." But the fact is, I don't write what I want to read either. Not truly. As a reader, I prefer stories that are 10,000-50,000 words long, but almost everything I've managed to finish writing over the years runs under 5,000--and my longest barely clocks in at 15,000 (which was a desperate scramble for a Big Bang project). Sure, I write about the characters and subjects that interest me as a reader, but just about everything I write is "too short". And I suspect I need to simply learn not to feel like a failure because of it--long stories just aren't the way my writing-brain works, and every time I've tried to force a large word count, the thing's fallen to pieces. (Every single damn time.)
...It's okay if I mostly write loosely-connected series of vignettes. If every time I've attempted NaNoWriMo things have ground to a halt after the first 5,000 words. I can enjoy the epics written by other people and not feel guilty because I haven't and likely never will produce one of my own. I DON'T NEED TO WRITE THAT BEST-SELLING NOVEL TO BE A GOOD WRITER.
*flings confetti and glitter*
Guys, I know this probably all sounds blatantly obvious to you, but I've been carrying this weight of unrecognized personal expectations around for years without realizing it. Almost multiple decades, in fact (I had a pretty rigid set of expectations for myself as a child; entirely in-born, nothing at all to do with my parents). I'm almost giddy with relief right now.