Just my two cents, haven't read the full debate.
Sure, Rare Farms are nice. But, it still takes a lot of time and effort to 'farm' the top50 to get these rare cards. I was trying for about 2 months to get ONE Eternity.. I ended up with 4 Discords and finally got my Eternity.
To be honest, if Zanz had implemented ANY other viable way of getting more than 1 rare card (either new quests, higher chances etc) then this problem wouldn't exist. Sure, it is abusing the game system and is highly unfair in a way - but if the game offered a more viable solution to get 'rare' cards, then like I said, this problem wouldn't exist.