Simpsons still is funny, it just doesn't hit the same highs as it once did, and occasionally hits really low lows, but it's not downright terrible.
I'd say Family Guy is downright terrible though. It's so ridiculously mean and ugh. It's funny once in a while, nowhere as funny as it was before it was canceled. I'm really disappointed that the Family Guy writers wrote that episode, because from everything I've seen/heard about it is it's too Family Guy and not enough Simpsons. Family Guy is just too mean, stuff that would never happen in The Simpsons. Because at the very least, The Simpsons can pull human emotion and heart, something Family Guy never does. I can't even excuse it for not doing that by being mean spirited kind of humor, because Archer/It's Always Sunny are the same way but can still feel grounded and human when they need to.
I am kind of excited for The Simpsons/Futurama crossover this season. I do hope it's more Futurama than The Simpsons.