To me it looks exactly like what the author says: mainstream, 
    corporate captured product marketing, in group signalling, an 
    aesthetic subculture... 

i'm well into middle age now, and i have always thought this about "subculture/counterculture" groups in general -- how are you even rebelling when you all look the same? you're conforming, just to the norms of a smaller group.

however, you're missing (at least!) a few major pillars of what's happening with the LGBT+ community.

1. for those who have (and still do) have to spend much of their lives hiding their true identities, just getting to express themselves openly and with pride is a joy. something that's hard to imagine if you've never had to hide.

2. being gay/trans/etc is a pretty material and fundamental part of one's identity. it's orders of magnitude different from "liking grunge music in 1993" or whatever.

3. it is not necessarily acceptable, or even safe, to be LGBT+ in many places or around many people. in that sense these shared and "stereotypical" aesthetics serve actual functional purposes - they allow LGBT folks to identify others who are not likely to negatively judge or persecute them.

    ...feigning angst and struggle

they're feigning? who are you to decide that?