His argument still stands. The fact that combinatorial optimization is difficult doesn't change the fact that the problem space is finite and can theoretically

His argument still stands. The fact that combinatorial optimization is difficult doesn't change the fact that the problem space is finite and can theoretically be enumerated by a very fast computer with lots of space. This also means that the heuristics that are typically used (that dramatically reduce the problem space at a rate tied to the size of the problem) can make the exploration of potential solutions much easier than it once was.