Funny, I'm the other way - I actually play multiplayer so rarely that I often consider it a minus when buying games... not because I think multiplayer is bad, but because especially when you have a small team, everything from writing a stable and functional netcode to balancing gameplay mechanics towards competitive fairness takes a lot of time and effort. And from my perspective as a player, I'd much rather that time go into crafting an experience I could enjoy and learn from in a single player environment, in my own time and at my own pace. But to each their own!
I totally do believe there's such a thing as "bad AI" - but I also think what gets labeled as "bad AI" is sometimes not quite what it seems. Games aren't played in the "real world" - they're played in a hyper-real environment with way more information available to the player more readily than in most real world situations. Players are often very experienced at playing games as a skill of its own, and think like game players or puzzle-solvers rather than real commanders. The most fundamental thing that often "kills" multiplayer war games and simulations for me is the competitive mindset that many players go into these games with - because it results in play styles that, while intellectually stimulating, challenging, and even creative, don't line up well with "the real world" at all. So I often find that AI behaviour gets labeled as "bad" in situations even where it's actually plausible and lines up well with the real world - just that the player has way more information and free choice than the real world would offer, and crushes the AI as a result, feeling underwhelmed and under-challenged as a result.
For me personally, I like using war games as tools to get an understanding of history or "reality" (whatever one might mean by that term) - and as a result, I prefer to approach games like this with a mindset that would be absolutely disastrous in multiplayer. I set house rules and limits on myself. The game can also help along - whether with things like order delays, scenario design, or by using the same AI behaviours for both player and enemy units. In that sense, Armored Brigade's design already seems to encourage delegating authority to AI. I would recommend anyone who finds Armored Brigade's AI too easy to try and avoid micromanagement and delegate as much as you can for friendly AI to sort out itself.
Ultimately, you can't make a game to please everybody. Doubly so, if you are a small developer. But you shouldn't be trying to make a game to please everybody - and, well, it's true that if you mostly like multiplayer, this might just not be a game for you. However, I would encourage people not to be too quick to make assumptions, and to try to play and enjoy on a game's own terms rather than only your own terms. Sometimes you might just discover something that's satisfying in a different way from your usual. Games like Armored Brigade are not made overnight, and are not made without thought - from its very early free versions, I could tell that a lot of thought went into Armored Brigade's design. It's not as though the developers here had no idea how to make a good game that results in satisfying play, or hadn't succeeded at it. It's just that to get the most out of it, you have to get on level with what it's trying to actually accomplish.
For my preference, I would've liked a campaign mode, but we can't have everything all the time, can we?