I disagree with this. They did have an arc, it just was more subdued, wasn't provoked by production, and hadn't come to fruition until after the show.
Ignoring the "nontent" criticism because it's subjective.
The main three criticisms were that the twins were drunks, poor losers, and Bongo "abuses Bingo."
-They kept to their word about not drinking again. Minus a single celebratory drink by Bongo after the show ended.
-They proved reliance on each other (and frankly most the "abuse" was pretty standard sibling stuff if I'm being honest). And do not blame each other for not trying hard enough or anything of that nature
-The most important part is that even after watching Bongo's drunk crash out, Bingo's crying moments and Drake man handle them, they both took it in stride pretty well and bounced back. No bad blood on the contestents or production. No excuses for when they had bad showings. And accountability for their short comings. Such as stating they felt bad about taking attention away from James when he won, even if that was the most valid crash out they had.
I honestly think the post tank stuff has only made me even more impressed by them, as even them saying it was clearly rigged for James Drake they followed up by saying he deserved that for how good he was.