I have a few theories. - Snow Leopard was the last $99 upgrade, and I think people like to convince themselves purchases were worth it. That effect is entirely

I have a few theories. - Snow Leopard was the last $99 upgrade, and I think people like to convince themselves purchases were worth it. That effect is entirely lost with free OS upgrades, I'm free to disparage them without feeling like an idiot for buying it. - Many people in enterprise & education stuck with SL for longer than they usually would have on the server, because it was the last OSX with an actual server release. This ends up with a "people who know what they're talking about are sticking with SL" narrative that gets propagated sans the understanding of _why_ they kept it around. - SL was the last release on physical media, which upsets the "they're turning my mac into a phone" narrative. Interestingly, when Snow Leopard was current, everyone held 10.4 Tiger up as the canonical release in much the same way they later did SL. Snow Leopard wasn't cool until it was already dead. Part of me suspects later releases haven't been able to take this mantle simply because they don't stick around long enough to make a name for themselves. (Although Sierra is starting to get there, thanks to a crowd of people who are too scared of APFS to upgrade to High Sierra).