Random walks only progress if they don't get trapped in a local minima. GP example is but one entirely contrived scenario. The point is that technological development depends on many factors and it's entirely plausible that some of them aren't strongly selected for.

This seems to be supported if you consider how long it took for humans to emerge and the fact that other fairly intelligent species exist alongside us but didn't follow the same path. If you suppose that technological development has a clear selection path then why isn't there any evidence of space fairing dinosaurs?