That was a nice moment, albeit one somewhat undone by TDKR's implication that many of those same hardened criminals gleefully participated in Bane's assault on the rich.
Nice and unrealistic IMO.
If it had been the real world those prisoners would have nuked the other boat in seconds. They're not lifers because they got caught jaywalking on a Tuesday or pissing on the sidewalk or something. We refer to them as hardened criminals because they are, in fact, hardened criminals. They're not nice people. Things like the assault on the rich would be just like the kind of stuff they had been doing which got them put away in the first place.