It’s not good at strategizing with all the options available to it given it’s micro ability, it has “one” strategy that leveraged the micro as much as it could, and when given a strategic challenge by mana, it didn’t know what to do.
They want to make an AI that can teach new ideas to humans. New strategies that human bodies are physically capable of executing, but no human was "smart enough" to think of yet. An example is when the AI built a high number of probes at the start. That's "smart".
The only way to train an AI to be able to come up with new ideas, is to force it to be "slow". Otherwise, it will just always do the easiest way to win, which is out-micro. There is nothing interesting about a game like that. That only shows the AI is fast, but it won't be clear that it's "smart"
Making an AI that wins by outsmarting humans, on the other hand, is what we are all interested in.
They don't, because AI doesn't use physical objects to move stuff in the game. AI just "thinks" that this stalker should blink and it blinks. Human player has to deal with inertia of his hand and of mouse.
If you want fair competition of micro - make a robot that watches screen through it's camera, moves mouse and presses keys to play starcraft.
Then the bandwith of the interface is the same for both players, and we can compare their micro.
In that context, you can't really measure strategy without accounting for timing/speed because a lot of tactics and strategies only become viable once the player has the required speed to actually realize them aka "micro".