That's a good point. Don't believe I've ever seen a broken rear either. Their pulleys do break though, and they're kind of hard to find.
But then, Campy pulleys break too. But I have spares of those.
I think the Simplex Criterium shifts pretty well. Better than the Prestige, IMO. The addition of the metal side plates helped, IMO.
But I didn't find it shifted any better than the Nuovo Record rear. Again..... IMO
Which hardly counts for much.

I also think the motivation for bashing Campagnolo N. Record rear derailleurs is ...em...suspect.
If it makes someone feel good to do it, though, you go.