Its a not a difficult concept to grasp that as this game ages, its playerbase shrinks so more people are having to rely on runs with bots that do their absolute darndest to screw up a run almost like they are programmed to do so?
Their stupidity is fine for champ runs, but legend and cata they turn into absolute farkin lemmings and just go out of their way to be dumb as hell.
Things like standing in poison puddles, getting farked up by minotaurs, grabbed by ever disabler in the game, getting stuck in ultimate weapons (looking at you grail knight and sister) not rezzing downed players, not jumping down ledges, not being able to path any environment that doesnt have flat ground, not joking any map that has elevation or uneven ground and bots just eat damage like they are using their faces as a shield.
However, even in their mentally deficient state, they are still better than 85% of this games playerbase which says allot