And a lot of people only get a new access point when they either receive a new router from their providers or change providers.
This is not uncommon to have the same wireless access point for a decade or so and people are generally fine with it. Also most people don't even know there are different revisions of the wifi standard and if you say 802.11 they will just look at you with clueless eyes.
I am not saying it is ok for any OS to not support it but it doesn't necessarily affect everyone's life.
Some work is done on that front though:
https://wiki.freebsd.org/WiFi/80211ac