Massive projects were started without much rational sense just to beat the other side in an imaginary race (and a very concrete military race). What's the point of landing a man on the moon, if the technology to do so was so rushed and held together by duct tape that it wasn't useful for anything else? What's the point of the Space Shuttle if launches were more expensive than disposable rockets? What's the point of the Buran, if the Soviets didn't feel like they need an answer to the space shuttle "just in case", even though they couldn't see any point in the shuttle design (except as a nuke carrier)?
Etc... etc... the list goes on for both sides. I rather have slow and steady progress that actually makes economical and scientific sense in the long run.
PS: I thought the secret of Roman concrete had been cracked long ago (a certain type of volcanic ash)? But it's just not economical to produce large quantities since modern sky scrapers are not expected to "survive" for thousands of years anyway (and AFAIK the Romans didn't know much about the special properties of their concrete either, it more or less was a "happy little accident").