This is what it looks like when your lame comedy catches up with you.
Seth McFarlane should have ignored the mash-up of two different episodes and realized that he has created a show that can be taken out of context because it patently ignores context every time it is aired.
What is not in dispute is that he thought it would be funny for one of his characters to run over people who are running the Boston Marathon; he also thought it would be funny for that same character to use a cell phone to detonate a remote controlled bomb. No one put a gun to McFarlane's head and made him come up with these premises and no one forced him to put these things out there. His lame comedy skills did that and now he's been caught short by the shabby work that he has done.
How is that anyone else's fault? He put those things out there, thinking they were funny, and now people realize what a bunch of useless crap he's been throwing out there. Only Fox would let him have three shows and think it was a good idea.