Feast was only fun at medium or high level for a healer.
Low elo Feast was pure fucking cancer, for healers at least.
Because everyone had the mentality of "Kill enemy healer = win", everyone would just focus your ass and no one would help you, they were all on the enemy healer, so good healers who went through that hell were rare, making the queues for it even longer since of course nobody want to be the masochist getting focused.

That was always my main problem with Feast to be honest, the mode put an incredible responsibility on a single player and most games were basically just "Your healer VS enemy Healer".
Of course, many people actually loved that, and it was also really fun to play at high elo (because only focusing healers would just get you pick by the enemy dps)

There's also the fact that SCH wasn't that good in it, even after multiple buff.