The villain will likely call close to any two in the BB, and he will checkraise that flop with any pair/any draw/sometimes total air. When he bets the turn and you raise and he calls we now know the villain is not bluffing so his range is now any pair/any draw. I hope you can see that even with this bad river card you are just too likely to be ahead here not to bet. I would not even qualify this as a thin value bet, IMO this is a standard value bet. If I'm checkraised I am never folding to this type of player, I would just call.