I never said I was a single-player player... but I am.

Since your question sounded honest, I'll honor it with an answer.
I know what I'm missing, because I've played plenty of multiplayer.
Yes, it gets boring playing the AI.
Yes, I wish I had a fantastic opponent that knew how to use innovative tactics and gave me a fun, unpredictable game.
No, I don't get that when I play MP.
Now, I'm not speaking of this game, in particular, because honestly I've never played THIS game online. However, reading the forums it's not hard to tell that it's just like every game I have played online, and that's not surprising, since people are people are people, no matter what the game.
Single-player versus multiplayer is a tradeoff, and I think it's a lopsided one.
Playing multiplayer I supposedly get a smarter opponent, but what I really get is one that likes to spam one unit that's been proven to be the best, or rush wildly to win the game within the first ten seconds, (because a win is a win and if you can't stop a rush you're a noob that deserves to lose) or carefully practices some lame technique, no matter how inappropriate to the game setting.
The end result is amost always that the game suddenly has a quarter as many units as it should (Because only a noob would build the other 3/4!), and is in many ways more predictable in its tactics than in single-player!
And then there's immersion... When I'm playing Company of Heroes, for instance, I'm not just engaging in a competitive activity for the sake of winning. I'm playing to be immersed in the setting of WWII. That means that I'm not going to have fun facing down Ranger spam, or a whole army of nothing but Kettenkrads, or whatever other stupid tactic is in fashion this week, no matter how challenging or effective it is.
I'm not going to have fun if it's over after my starting unit killed his starting unit faster than it killed mine, or vice-versa.
So, if you can find me an opponent that plays the game to have fun and actually enjoy the setting, and can do that at any time of the day or night, any day of the week, and doesn't mind stopping at any time so I can eat or indulge any other whim I have, then I'll enjoy MP as much as I enjoy SP.
Until then, I'll just have to put up with the (theoretically) sub-par AI, and go on thinking I'm getting a pretty good deal.
TRANSLATION: "People say that real people are smarter than the AI, but I have yet to see that be true." 