So I am in a 1/2 game with ~100bb effective stacks. I am in the sb with KJo. The 4 ppl limp including the CO and button. I complete instead of reraising because every is playing no fold'em hold'em pre-flop and folding a ton post flop. Flop comes 33j rainbow. From my observations the past 4 hours I noticed people will fold top mid kicker if bet into on the flop but will call down if they bet first even with mid pair. I check hoping someone with JT, Qj, a pp like 6's or some random j2s hand bets. Checks to the button who bets $10 into $12. I call, the bb calls and everyone else folds. Turn is an offsuit 7 so no possible flush draw. I bet $25, the bb folds and the button insta-min raises. The min raise confused me as I had only seen people doing it for value so far. I ended up folding thinking he could have had a3 or k3s or maybe AJ. Everyone has been so passive I couldn't see being raised at all with JT, QJ, or any pair. Was that just too weak a fold, or am I always running into better here with a raise at the 1/2 level?