This is an experiment to try to prevent players new to the game from being discouraged because of long queue times and brutal competition from experienced players. There is a steep learning curve at the beginning of your Mythgard experience, which creates a wide MMR gap between new players and others, making it harder for new players to match. Some people come in and immediately turn off the "match with AI" check box and then have a bad experience, when they'd be better off playing a few more bot matches until they learn the game.

At the same time as this change, we added MMR bonuses for playing against AIs, so I hoped complaints like yours would work themselves out quickly. I'm going to disable the feature now, and we'll try something else next time we work on the matchmaker.