CTFs are not free-for-all competitions, they are clearly time-bounded and designed for enjoyment. Having a team show up with a zero day chain for Linux that they designed for a year spoils the enjoyment of everyone else.
rming the CTF infra spoils the enjoyment of everyone else, winning because you’re the best and showed up with a cool exploit chain isn’t spoiling anything for anyone.
Right, so my point is that hacking everyone playing the CTF or the infrastructure is similar to running rm. Using a zero day on a challenge to get a flag is often allowed and even seen as amusing.
If you hack the infra to get all the flags it's really pretty close to just nuking the competition then and there isn't it? What's the point for everyone else to continue after that?
CTFs are (usually) hacking competitions for hackers, what else would you expect?