It's also much cheaper, since it has per-minute billing rather than per-month billing, and no setup fee. Getting temporary access to 100 Hetzner servers would cost you ~€10,000, because you have to pay a setup fee plus a minimum one month rental for each one, while it looks like it'd only cost you ~€100 to get 100x OnMetal servers for an hour. If someone stands to benefit enough, you'd be screwed in either situation, but it lowers the cost of opportunistically sowing some malware.