One thing I really liked about their show, even when I disagreed with their conclusions, they explained how they came to them rather than call people stupid for not believing as they did.
I mean they definitely called a bunch of college students stupid in the environmentalism episode for falling for the old dihydrogen monoxide bit and then used that to imply that environmentalism was stupid.
Its a valid criticism though... many many people say things like 'believe science' while themselves having a very thin grasp on fundamental scientific principles and knowledge. Not that DiHydrogen Monoxide is critical knowledge, but just that scientific literacy is shockingly lower than scientific evangelism
That's something they've acknowledged too, and had planned on a "Bullshit of Bullshit" finale:
"We promised to do a Penn & Teller: Bullshit of Bullshit! show as our last show in the series, but we walked away for a better deal and didn’t know when we did our last show that it was our last show. We still have hopes of going back and fixing some stuff about climate change, weight loss, secondhand smoke, and other things..."