It is really sad what kind of precedent this is setting. Hollywood is already too risk-averse as it is, and now it is going to get even worse.
I think that Judd Apatow and Jimmy Kimmel said it best on twitter..
"I think it is disgraceful that these theaters are not showing The Interview. Will they pull any movie that gets an anonymous threat now?" - Judd Apatow
" @JuddApatow I agree wholeheartedly. An un-American act of cowardice that validates terrorist actions and sets a terrifying precedent." - Jimmy Kimmel
This movie has unleashed a massive hack upon your company. Tons of damage has been done.
Now the hackers say releasing the movie is going to result in violence against movie theaters that show it. Logically you know this can't happen, but there is certainly a chance some psycho acting on his own behalf could attack a screening after all the publicity this has generated.
Do you take the chance of releasing a mid-budget stoner comedy knowing that you will ultimately be held responsible if some crazy dude attacks a theater?