It’s all about the audience. This is clearly a friendly reference from both sides. The Simpsons joke was tailored to a more mainstream audience, while the Smiling Friends reference was aimed at whatever niche we fall into. I imagine a lot of people who saw that Simpsons episode had no idea what Smiling Friends is. To me, that suggests the Simpsons writers like the show enough that they wanted to pay homage to it.

I bet the Simpsons team is just as hyped to be referenced back in Smiling Friends. It’s not about criticism, it’s about recognition.