No point trying to improve the AI in my opinion. The game was made for online play anyway. Just my two cents.
The game is multiplayer, that includes LAN too. Sometimes a few bots can supplement and odd numbered team. Bots help newbies afraid of criticism to train alone and improve. Bots let you hop in and test maps, weapons, shooting positions and strategies without hurting you rep. Bots let you play on long train rides, or any other wifi-free zone.
Bots are an essential tool in player development, and the more the AI grows the better players will get.
What if your internet is out for a few weeks, bots help the downtime grind, but sucky bots just get annoying.