I beg to differ, as I greatly enjoy casting Turn Evil on the undead adds along the hallway up to Ptah, in Halls of Origination.
This is a silly thread, though.
Warlocks have an interrupt in the form of a Felhound.
"It's got a 24 second cooldown!"
So does Counterspell from Mages, and Silencing Shot is close, at 20 seconds - something ONLY Marksmanship Hunters can use.
Silence - a Shadow Priest-only spell (and one not every one has), has a 45 second cooldown!
ANY Warlock can use a Felhound, and thus, Spell Lock.
"But it costs me DPS to use!"
It costs Rogues DPS to save energy for Kick.
It costs Warriors DPS to save rage for Pummel/Shield Bash.
Arguably, Silence causes a DPS loss, as it is not typically part of a PvE Shadow Priest's spec.
It costs Prot Paladins DPS (and thus TPS) to save Avenger's Shield (not to mention a GCD for it), and more to save a GCD for Hammer of Justice. (Fortunately, in the next patch, Rebuke will be baseline.)
You already HAVE an interrupt.
The fights that require you to give your absolute max DPS, damning everything else, are not the same as the fights that require reliable and consistent interrupts. And if you are too obsessed with your own numbers to contribute to the overall success of a group, then you have larger problems to deal with.
/thread
Don't trip over your e-peen on the way out.