From what other people are saying, it sounds like Hetzner is the Walmart of service providers. You wouldn't see a traffic jam in the Walmart parking lot and then become indignant that they didn't have valet parking automatically start up to clear the parking lot traffic.
Detecting these is trivial. Actually blocking them requires significant bandwidth capacity and equipment. Do you expect them to make that investment? You have the choice between cheap hosting and DDOS protected hosting. Buying cheap hosting then complaining that your host is not providing expensive services is silly.
Or are they unable to properly detect a DDoS and would also take off a server that hosts a web page mentioned on Hacker News?
How do other hosters handle this situation?