It doesn’t matter if all talents were trash, it’s still bad design and has obviously been forgotten.
Secondly, you assumption is wrong, you don’t get 4x the coins if you are alone, so there goes that out the window. I imagine I read somewhere here before that you get a slight coin boost for each bot (and quick testing had me getting between 35-42 coins solo), but don’t quote me on that. Even if that was the case, the amount is negligible and should be totally inline, considering how trash bots are in this game, and especially in this mode.
Lastly, since most talents are so God damn trash like you are implying here, why does it matter so much to you that someone potentially inflates their total gold amount by what constitutes probably something around +5% gold across the entire campaign?
The concept of being against such obvious improvements is such an alien concept to me. It truly is baffling.
edit:
Yup, there it is.