"It's not true to say there are no good AIs. The Command Ops series has one, the AI in TOAW 3 is very good and there are other examples."
I own the Panther Games series as well as TOAW III as well as likely all the other wargames you own
I LIKE Panthers Games for the way they were designed. I like the forced command and control logic of not responding immediately to a simple mouse click.
But the thing is, a challenge from an AI is like a good joke, good the first time, but once you have heard it, often there is nothing special left. I have noticed, that the best part of Battle Academy is always the first time you play any of the battles in the campaigns, as you don't know the battle yet, won't know the reinforcement schedule and as a result, if you make bad choices, you pay for it. On the third play through though, the AI is usually at a disadvantage. Now vs a human, BA is definitely a challenge.
Too many regard a game as 'challenging' for the wrong reasons. Yes WitE can be challenging, but so is painting your kitchen with a toothbrush

And thus, it is often not about the complexity, but rather the level of the work load. The AI won't be actually better, you are simply making yourself overloaded. I prefer to play Civilization on a massive map, with as many AI civs as possible, just to max out the work load. Because on Deity level, you vs a single AI on a small map, it's no real challenge. The AI will not 'know' the game in advance whereas the human will remember all the previous games, will thus be 'thinking' which is the best way to approach each map they find themselves on.
WiF will be considered a great boon to every wargamer that essentially couldn't care if computer wargames were ever given AIs at all.
Because every wargamer, regardless of AI fan or not, lives in a home that likely simply will never have a room dedicated solely to playing maps best set up in a warehouse.
Those that insist on playing vs an AI no doubt will desire the AI first. Likely will have the same laundry list of reasons I personally don't consider justifiable. Not enough people to play... not enough time...live in the wrong area... I make my life conform to my needs. It's not like there are no games out there that are global grand strategy and with an AI

I can name several.
I have too many too complicated wargames, and not enough sufficiently interested non wargamer friends.