Because riots department def cant make bots. As predictable and as aggressive as a bronze 5, skill shot accuracy of a scripter. Ive seen bots made by others that play like a gold player to the point you wouldnt even know if you played vs it. The fact riot just has these half ass bots along with the fact that riot doesn't do anything unless there is a 5k upvoted reddit post goes to show they give 0 shits about their game.
Why would they want to becomes the question. Bots as they are help new players fell confident enough to jump into PvP which is what League is built around. Why would they not want to invest their time and energy into the game modes that hold the most players?
As a side note it would be dumb for Riot to hire any sort of scripter when they already have everything they need right now. In case you missed the news a while back Riot sued and won against a scripting website with the results giving them the site and everything connected to it. All that's needed is to do some tweeks and most of those scripts could be bots in no time.
and why should they?
This is a PvP game.
They have bots far better than those we see. The reason they don't use them is that they consume too much server cpu. The ones we have get to eke by on a miniscule amount of processing power (hence the suckage).
