This particular question has interesting aspects which helped it make it pass muster. Also, it's seems fair to suppose the asker just didn't know what term to search for to get the answer to their question. 'Single-use rockets' yields nothing relevant. 'Reusable rocket' yields a list of high quality reports that go into all the aspects. One could have simply told them what to search for and then closed the question.
However, it is the sort of question it is tempting to answer, because there is a vast public out there who only occasionally get interested in space exploration, and this was a chance to quickly introduce them to key concepts in a digestible way. The answers now neatly fill a gap by very briefly explaining that reusability is very hard, no system is fully reusable, and the task is even harder as payloads and velocities increase. The answer it required was complex enough to be interesting, and remains undocumented in neat brief formats like SE.
I agree with what Machavity and called2voyage have said, but I note that the question continues to have 3 times the votes as the answer, so I added a bit.