I sort of agree, it's perplexing in a way, but that quote I paraphrased says a lot too... He wasn't confident in his defense, nor should he have been, and ultimately that onside kick let them get their points that (given the game thus far) they would've gotten anyway most likely, and so the Steelers still had time on the clock... If it worked, you had another offensive chance at spreading a lead to 6 or 10, if it didn't work you were giving up the points you probably were going to give up anyway a little faster and still have a shot at getting down field for the points needed to tie or win before the clock ran out.
From the perspective of not having confidence that your defense, and more to the point your secondary, can stop a clicking pass offense... and time management... it makes more sense I think, but was that what some of the intent was?
I still don't think I'd have done it, but it worked out positively in the end though.
