WoD had only raiding as PVE endgame without mythic-plus, class tuning changes were done in/after heroic weeks, so FOTM was allways for a very short time frame and the legendary progression was just as cruel for alts as anything else from LEGION/BFA so people asked themselfs if its worth to jump the next FOTM train when it only last for a few weeks/months.
That changed a lot in LEGION/BFA. We dont have real class tuning each raid tier anymore, some outliers from LEGION even carried over to BfA for specific mechanics and it outweights in many cases any gear progression disadvantages you could have with rerolling all the time.
Just look at outlaw rogues in mythic for 3 season outperforming 20+ ilvl gear advantage simply because of mechanical/tuning issues. DoT specs outperferming everything in the current raid tiers, so you had no real disadvantages if you choose to reroll any of the broken classes, because the tunning was so far off, that gearprogression was basicly a non-factor.
Its bring the class not the player and you are even gifted with the lack of real balance changes. The reasons? Last time the wording was something like "we dont want to disturb the raid progression", so they change nothing PRE-content patch, they change nothing in the heroic week and they change nothing in the mythic week, even when they got all the data to track the outliers.
And people are surprised, SHOCKED!, that the PVE community was done with this crap gave up and moved to mythic-plus with full META setups, because there is no balance punishment to fear.
I enjoy playing with other players and it doesnt matter for me what aspects of this MMO they like.
What I dont really like the advantage seeking FOTM reroll crowd, the players who basicly hate the class they play but they still choose it because it "performs" better. The whole situation about this kind of gaming choice brings negativity and I try to stay as far away from thos kind of players as I can, for my own sake.