I had numerous situations where systemd didn't let me abort a hanging service startup during boot or stop during shutdown.
So what do I do now, systemd? Wait till infinity??
That never happened while using other init systems. Because they simply fail properly ("sorry I did my best to stop this, I needed a SIGKILL finally"). Or simply let me log in: "sorry, some services failed to start and now it's a huge mess, but at least you can log in and fix it.".