It might be bad of me, but I generally enjoy when that happens. It's hard to remain impartial all the time. I keep failing my will save.![]()
My players don't enjoy it (either the process or the results) so I don't enjoy it. It means my friends are not having as good a time as they otherwise might have.
This is not to say I care whether their plan will succeed or fail. But they can fail without spending a third of the session figuring out exactly how they'll fail.