I am actually curious - why do people like Assassin Vine? I feel like Treant is a pretty clear choice, because Treebeard was an awesome character in LotR. Shambling Mounds = Swamp Thing, and he's pretty awesome post Alan Moore.
Shrieker just looks like it's been ignored, and so doesn't really move much. Probably because of all the up-down against and for other plants. I was surprised that it didn't get the same down-voting that the other fungi did frankly...
Maybe GMs like using Assassin vines in their adventures? But that's the only reason I can see voting for it. Not really understanding the love for it...