AC gives you cheap synchronous magnet motors. These are what you find in most off the shelf power tools. But, they can;t be electrically speed varied, and don't produce max torque from a standstill (treadmills for example use DC motors for this reason).

Its not a show stopping constraint anymore - so much so that a ton of electrical appliances can happily run directly off of 200-300V DC because it just bypasses their internal rectifiers.