Season 2 and No Kwang Soo

I'm really pissed off that they're replacing Lee Kwang Soo as the male lead in season 2.  I don't understand why.  He's a popular actor and a very good one.  They're replacing him with eye candy, Sung Hoon.  Actually, they're replacing the entire cast.  Mores the pity.  I think they're screwing the pooch with this one.  It wasn't broke, but they're trying to fix it?  I'm curious as to how it does, but I can't imagine this new cast being funnier than the original.

I don't understand why wouldn't they cast Kwang again? It won't go well as season 1 did I bet... unbelievable ...