I totally agree. There are many good guides about how to pick and right equip bots to play Cata solo. Also about the tactics and strategy of such a game. There is nothing to say about the Legend, it is very good with bots.
Another thing is that bots have bugs. Bugs should be fixed (but new ones are added instead, as with patch 3.3 about bots and ammo).
Personally, I would also like the functions of manual control of bots, for example, based on the Social Wheel and marking targets.
In any case, improving bots and solo play can in no way to harm those who want multiplayer expeience only. They can do it themselves.