Songwriting.
I don't think these songs sound tossed off at all. Most of them get pretty complex; it's a nice idea, thinking these three could just get a studio and create huge mountains of sound on the fly, but there it was probably a bit more work than all that.

ZMF only likes stuff that totally fucking owns.

Why…
…do you guys subject yourself to these every year?

I got the impression they were doing a mutual joke thing. I think that's just the style of the interview. They probably know each other personally.

Seconded.

I think the joke is on normal citizens who believe that "selling out" is a real thing in their lives.