Well that's not my opinion. JKA doesn't use overbright (or if it has the capability it's turned off by default I forget), but it's on automatically in JKO.
You can manually turn off overbright but then the maps generally look to dark. You could map for it turned off, but most players wouldn't bother to manually turn it off if you explained what to do in the readme.
That's why I like to turn it off with a shader in jko so that everyone is seeing the same brightness and not seeing big white lightburns.