I honestly really like this one. The point of it is not to "be unfunny", it's to tell a relatable story. If you've been in Twilight's situation before, watching your friends laugh at in-jokes you don't find funny in the least, you'll get it. The in-jokes themselves are not the comedy that holds the episode, the comedy is in Twilight's struggle to uncover why something she doesn't find funny has brought her friends close to Discord. Like, you guys can find whatever you want funny or unfunny, but...I hope you and so many other people I see talk about this episode don't really think the entire episode was meant to be unfunny.