I've figured it all out now, why blizzard won't ban bots. It's not about the money they would lose from player-owned bots or gold farmers, because realistically those are an extremely small minority who just so happen to be benefiting from the current circumstances by accident. With the current situation it's just too much of a hassle to identify player-owned bots from well... The Borg I'm about to expose. The majority of bots you see now are not a coincidence, no other expansions had Borg vs Borg battles in pvp ending in stalemates. The reason there are so many bots now is because..... dramatic pause..... BLIZZARD IS BOTTING! Yes now you're probably going through it in your head realizing just how true it may very well be, and how insanely beneficial it is for Blizzard if it IS true.
Many systems are already in place that allow players to continually play with themselves regardless of content, and disillusion players into thinking the game is full of other players to play with. Realistically the game doesn't even have as many active players as League of Legends does. It's quite sad when you step back to realize it; cross realm zones (it's like expansion release day-1 in every zone now, because 20 realms are slapped together), raid finder, dungeon finder, battlegrounds, arena/RBG finder is next mark my words. All of these automated queue processes also have a slew of automated bots run by Blizzard to milk the cash cow majority who would never second-guess them. It's all a plot to uphold a fake image. Look closer in your dungeon runs at those "bad" dps, because sometimes they're not even human.
If you don't believe me then I challenge you to do your research by simply adding 10-20 known bots to your friends list. Check up on those bots once in a while, look for raid achievements or pvp achieves, check to see if they're making any gold or farming anything. Most bots are just empty voids not even farming mobs, just made to deceive the majority.