Someone liked a Tumblr post of mine from 2014 about the 00s indie boom, and I’m still interested in the first point here: why, after two decades of mainstream incursions under the moniker of college / alt / grunge rock, did “indie” become the accepted term for this style of music around about 2005?

I think it was a combo of anxieties about "selling out" (which today seem like a quaint luxury) and a sort of testosterone purge from the more underground part of the scene. Like, the "wrong people" started showing up at grunge concerts in the '90s as "alternative" became the term for the mainstream

To me, what became coded as "indie" was an avoidance of overt masculinity and sexuality, at least in the sound, so that it didn't draw in potentially problematic elements (i.e. the "jock bullies" who got into grunge). Of course some indie musicians were still toxic-manipulator types themselves