"You haven't earned them though" - Not up to you decide what I did and did not earn. Though from my point of view, I have it, I earned it.
"In a truly competitive game mode, your rewards would be subject to decay or replacing " - No? Players earn unique rewards for being the best in a particular season in a lot of different games.
"If you were to not qualify once again on the board you should have everything taken away from you" - Again no? If I got a top500 spray in Overwatch for season 10, I don't lose it if I am not top 500 in season 11. If I win the superbowl in 2018, I don't lose my ring if I don't in 2019.
"That would be worthy of praise and pride and an actual test of skill, as you would actually have to be constantly playing and facing an ever growing competition." - That's not how competition works? It means you were the best in that given time period, not that you always have to be the best forever or we take away your shiny.
"wasted unhealthy amounts of time on it" - Wasted unhealthy amounts of time??? You do know this is an MMO forums right? The name of the game is wasting unhealthy amounts of time lmao. To your other points, I can't control the people who violate ToS, SE does. I report players all the time, and if nothing happens, that's on SE, I earned my place.
"An unworthy piece of content memed to hell and back which sadly hides some of the better designed mounts and glamours." - This can literally be said about any other piece of content anyone doesn't like.
Feast is by no means perfect, no one will argue you on that, but it has been enjoyable enough for those who do enjoy it to play it over the years despite the rewards(and there are some ugly ones too). People like yourself, who don't even play PVP to begin with, just get all bent out of shape when a cool thing drops that you don't care enough to get when it was relevant to do so.