Each NP-complete problem is in fact a family of problems. In the sense that you could compute an optimal sales route between a small number of cities or optimal

Each NP-complete problem is in fact a family of problems. In the sense that you could compute an optimal sales route between a small number of cities or optimally pack a very small knapsack in your head. I believe the point the posted article is making is that reasonable progress has been made against such problems of sizes that seem 'large' in terms of normal human experience, through brute-force computation and clever heuristic tricks. That doesn't mean they don't scale in the expected way or that a true shortcut has been found.