First off, the family looks.....different.
They were originally in short animation bumpers on the Tracey Ullman Show.
I actually had nightmares the first time I saw the Tracey Ullman-style Simpsons. Brace yourself:
|When a Sea Monkey jumps in yellow food coloring, you get this.|
Aside from that, I'm glad the show evolved into what it did, and that they still don't look like demons.