That's one way of looking at it. An alternative view point: By not using a general principle, a sales pitch could ambush you with a new scenario that isn't in

That's one way of looking at it. An alternative view point: By not using a general principle, a sales pitch could ambush you with a new scenario that isn't in your list of specifics. In that case, it's easier to learn to be dogmatic in saying 'Are you a legit business? Then no freebies for you!'