(Thinking of a new title for this space)
They fucked Metalocalypse the same way with a cliffhanger.
Considering how poorly the 1st season was received, I'm rather impressed that Supergirl was able to make it to 6 Seasons given its move to the CW.
I mean it's CW don't they give everything at least 3 seasons? Supernatural could have run longer than the Simpsons if it wanted to I'm pretty sure.