No reason to bother testers with stuff we already know...
Playing the SS standard AI was only worth it to see the new units and races. Going multiplayer isn't an option, I can't be bothered with wait times between games, not being able to pause or quit in the middle of a match, and the social side effects of starting to care about my automatch rating.
I'd rather test your perhaps slightly buggy SS Advanced AI than not play SS at all, so it really isn't any bother