That's a baseless assertion -- legality and morality are independent and only coincidentally aligned. Unless you want to start telling us about the ethical necessity upheld by the farm subsidy bill.
Clearly it would be immoral for you to intentionally provide a source of liquidity for stolen goods. How does that show anything about your gambler?
They are both separate examples of contracts that are consensual and without coercion, but are immoral, both for different reasons. My goal was to find a counter-example to the statement that "All consensual and non-coercive transactions are ethical.". Once that example was found, expanding from there.
They were discussing morality, not legality. There is a difference. You can base your decision to do/not do something because (you feel) it is immoral, whether it is illegal or not.
Often legality and morality do align (but really not as often as you'd think), and this is fortunate, because it allows good people an easy mental short-cut for weighing one's actions based on legality (and punishment), as well as protecting the weaker-willed parts of society that often end up on the wrong end of moral decisions by people like sneak, who'd let people drink themselves to death because if everybody was completely free they'd surely decide out of their own free will to do what's best for them and nobody would ever prey on the weak-willed like that, ever.
