Have you even read the thread? I never said there is anything wrong with tubs. My Gaboon vipers are in tubs right now...
Just because i haven't kept them myself doesn't mean i don't know anything about them. My friends keep and breed them, i know more than my fair share thanks. It's all opinion at the end of the day, i think my way is right and the others wrong. Simple as, it's not a big deal.
I used 'burrowers' loosely, as they like to bury themselves in the substrate and just leave their heads exposed.
I'm not denying that anyone with half a brain cell can keep hots. But you give a nasicornis or rhinoceros/gabonica to someone inexperienced it's quite likely it will end up dying, give royal to someone inexperienced and 99% of the time it will be fine. You obviously don't know anything about Bitis as a genus by your statement "They are slow and sluggish".