Totally agree with your point and I think it is also the reason why we today don't have planes that are so fast as the engineers back in the days dreamt of.

Maybe we don't understand the need for it right now, but if we had kept on improving and "wasting money" on improving the speed and finding new materials we might already would have solved space travel.

As the author points out, spending money on bombs were more important and I don't understand how this is a good thing.