im aware, i mainly play epics, but think about the main playerbase who doesn’t do any pvp at all. to them we are all toxic and shame them for bad rating. of course everyone wants to be able to judge someone to see if they are good, but nobody wants to be judged.
if you remove rating from the armory, then you remove a lot of the toxic rating shaming players like to partake in, you can still keep it game shown when people post a group or apply, or perhaps on /inspect, but most casuals see stuff where a pvpers talk 
to each other about rating and they want nothing to do with it.
as for unrated play, the people who are into that are mostly still playing, but it is a shrinking population, we haven’t had any new rewards in the unrated world since bfa. and a lot of people didn’t come back after SL.
im 100% serious, and yes i just had this discussion in disc about zero sum and non-zero sum rewards and their effects on the game. the fact is the average wow player is a supercasual these days and they don’t want to put up with zero-sum rewards. for most active full time rated pvpers the seasonal rewards are generally participation rewards already, its only the glad mount and seasonal titles that really mean anything to pvpers and that even varies by the season.
a progress bar that fills just from participation is something supercasuals can do. granted, we don’t want people just afking away in random bgs and epics, so the reward on loss is more of a non-zero sum reward for your time. one shouldn’t expect to fully fill the bar and get the seasonal mount and elite set by afking losing games. more of a you get something instead of nothing sort of deal.
i don’t play for rating, i usually just push for the elite mog and stop because i have my niche i enjoy already, arena is a chore for me, but you have to think about what stops new players, from a psychological perspective they need to feel like they are safe to fail, safe from being made fun of, and safe from feeling their own inner shame from failure. the current pvp world is very much one which only allows those willing and brave enough to step into the spotlight to succeed.
if casuals aren’t interested in playing with and against hardcore tryhards and the unrated modes don’t offer any seasonal rewards or new rewards, then casuals aren’t going to see a reason to pvp.
one other thing i have thought would be a good addition is to block names on rosters, in unrated block them for the enemy team until the match starts, in rated solo, block them all match, and in rated 2s/3s block them for the enemy team until match ends.
