This is definitly not impossible for humans. High level SC players are able to keep track of the mineral and gas spendings of their opponent in the early game (After the early game there is usually no complete information to calculate this). Just seeing the timing of taking the gas geysers gives you information about the earliest possible time a certain unit/building can be produced.

Of course a AI can scout more and take more variables into account but humans are surprisingly good at this too.

> Imho, beating humans to StarCraft isn't a big deal in itself, but it would need a lot of work to build the AI to deal with the game's complexity. But it's merely domain specific work that has little to no interest on AI in general.

The same thing was said about early chess AIs and the Alpha GO project. In the end both lead to major advancements in AI. If you solve the domain specific problem starcraft you could easily apply the gained knowledge to similiar problems.