Pfffft... Do you know how awkward it is to make an AI that can beat a human without cheating?
Ok so, I'll come clean, it can spawn majors, but not for everything. They were added to certain situations to patch up weak areas of the AI as John discovered ways to bleed it to death.
First of all, depending on the difficulty, the AI colony starts off with different compositions of pre-built brood chambers, Normal mode is about on-par with the player. The AI builds more nurseries as it can afford them (minors, mediae and majors), and also keeps a bank for re-spawns which it increases as the level goes on. The harvesting groups out on the map are not cheating, and the reinforcement majors are not cheating either. It took a long time to get all of that working well (having the AI scan for the best place to get food from, or when defending, choose the best location to send their reinforcements and also when it is wise to retreat). In the last few months before release, during testing, certain exploits were discovered - for example, you could camp outside the enemy nest and kill reinforcements one by one until they had no resources left. To make a sensible response to that, the AI needs to think about where its ants are in the nest, how many are outside, how many eggs it has, how to reassign workers, etc. Its a lot of work, and I had 20 other things on my plate - the music, the formicarium AI, the army ant mission, sound effects, movement bugs, other bugs, and other bugs... So you can imagine how tempting it was to just plug the issue by spawning some free majors out of a hole underground
and so that's what I did.
The final attacks don't really need to be free Majors and I wouldn't have set it up like that, but that part literally came in 2 weeks before release (after it dawned on us that in most cases the end game of 3.1 was a bit predictable after a point) - we had to contact the narrator last minute to get him to do a couple of lines to support it. It was 1-2 days of testing to do it properly, vs a couple of hours to tack on more free Majors and I just didn't have the time.
As we do more AI colonies, things will evolve and I will always be trying to push it to play without cheating.