Ai raiders have been proposed nearly since the start of the game. Here's somebody asking for them back in 2013.
The basic problem is that it's really hard to make realistic AI that can emulate a human raider, so that leaves you with the choice of static enemies, which are not very fun to take down in your own compound. Plus, if you want to face off against HERC, you can either go to the Island or wait for the HERC Bunkers update.
If it's hard to make them similar to Human raiders, then don't. They don't need to think like a human player would, because they aren't, they are AI raiders. My assumption is that it wouldn't be hard making an AI that would adapt to the bases of other players because there are a limited number of base variations that are possible. Why? Because the there is a limited amount of space, X, that is available for constructions to be built on. Think of this space as a chess board. And everything on it, as a chess piece. Is it impossible to make an AI to adapt to limited number of piece and place combinations possible? No, otherwise digital chess games would not function properly. Yes, a lot of other factors would need to be put in, but my point is that it is possible to do. Maybe the reason why this has never been implemented is because that the time and effort needed to make such an AI is not economically feasible, at this point in time. Maybe they'll do it one day, Maybe they won't. Perhaps they need to work on getting at least 99.9% of the bugs fixed before they do add anything else into the game.
Edited by Fredswar1, 01 June 2017 - 11:33 PM.