From my perspective, with this clue, it the abundance of avenues to take. Even the clue itself - you had Far Side, Gary Larson, 2nd First Take, Midvale, School for Gifted, Push, Pull. Then, even when we've gotten to iZombie, there's been about 20 legitimate guesses from that point, and still none are correct. This one in particular is a tough clue because of the myriad of paths to take and because of how far down the rabbit hole we apparently have to go even if we pick the right initial path. Just my opinion though.