"but other alternatives (for example, hiring a thousand engineers and building a thousand planes a year) would have found the same answer"
Before MacCready came along, there were a thousand (well, a large number) of engineers building a thousand planes a year. But because these attempts were disjoint, there were all making the same mistakes and were slow to learn from them.
The point of the article (as I understood it) is that when you're working towards a goal, you usually don't fully understand why that goal may be difficult to achieve -- what the real problems are. This is why is import to get early feedback about whether or not you're on the right track, and to adjust your attempts accordingly.
Before MacCready came along, there were a thousand (well, a large number) of engineers building a thousand planes a year. But because these attempts were disjoint, there were all making the same mistakes and were slow to learn from them.
The point of the article (as I understood it) is that when you're working towards a goal, you usually don't fully understand why that goal may be difficult to achieve -- what the real problems are. This is why is import to get early feedback about whether or not you're on the right track, and to adjust your attempts accordingly.