Earlier quoted context omitted.
Also worth noting that it starts by imitation learning from pros. I'd be curious to see if the macro can be learned without imitation; a much harder challenge. Also, playing with full visibility as was mostly the case in the demonstration is quite lame...
If you learn, why not learn from the best, the pros? These people already have spent years figuring out what works and what doesn't. Why not draw from that pool of knowledge and instead spend extra time going through the same motions?
An AI trained from human strategy might end up more limited than one that could learn from scratch. It could be stuck in a local maximum of play and be unable to escape.
An AI technique that requires a large dataset of pro play to learn will be much more limited in terms of applying it to other games.