Where does the current flood of bots come from?

Currently it is rare to play an ARAM game without any bots. Maybe half the ARAM games are decided by how many and which bots each team gets. 3-4 bots in a team are not uncommon, 8-9 bots in a game not impossible. Most bots are very easy to spot for players (and Riot):

1.) Name is Western prename plus some added random letters in front or after, random low and high key. 2.) Icon is mostly sprout, wolf or rose (less often revive). 3.) Spells are snowball, exhaust or cleanse (stands out as 80% of human players take teleport). 4.) They are usually last to load, last to leave the base. 5.) They never communicate, but in rare cases give honor. 6) They usually kill almost nothing and die alot (and take green crosses when they don't need them). Although some Ashe bots reach level 4 because of their efficient auto attacks. 7.) In every champ rotation, some champs can be preferred by bots and can be 95% of this champ in a week. Mostly champs with good auto attacks (e.g. Ashe and Lucian) or very passive behavior (Soraka, Rakan), so they don't get exposed too fast. 8.) Obviously, they don't use skins and, I think, only FTP champs. 9.) At the start of the season, they could be easily spotted having no runes at all. But the bots have evolved since. They also used to get stuck on the green cross source, but that has "improved" as well.

There are other bots, but this is the most common. Given this very specific narrowly defined profile, the bots are most probably from the same team/company/source.

Now the question: Does anyone know which source launches these specific bots? And why does Riot not ban these easily indentified bots to make ARAM a game between human players again.