Ditch AI and you ditch a lot of customers. Period.
Myself included.

It needs to be a part of the sim, and an enjoyable part. If you prefer flying online against real pilots, then thats fine, but don't assume that everyone can or will. To consider online as the 'solution' is just another nail in the coffin. How many novice pilots will want to fire up their new game and go looking for real pilots to fly against...

No practice, no chance to get to grips with the plane...and straight into a potentially hostile environment. Or..maybe the whole online world just got fair and friendly? You can't guarantee that How many people bought into Warbirds etc. as their FIRST flightsim? I'm guessing not many.

How many RB pilots played the offline game for a while before going online? Most I would think.

Yes you need stable multiplay... but you MUST have good AI. And I refuse to believe that it is impossible to make AI pilots that can fly 3 or 4 basic tactics and be able to use the right one for the right plane. Usually, the AI just tries to circle....and if you fly a Zero or an I16 in IL2 FB against the AI in, say, a P38, you will see it making pathetic attempts to out-turn you. Keep it up and they lose speed and die. A good pilot knows HOW to use his plane. The AI should do the same. Thats all a novice needs!