Introducing bitcoin to someone is not necessarily bad, but convincing them to invest is a bad idea because we do not gain any benefit from it and can even endanger ourselves as in this case .
Actually you can get benefit if you convince them to invest and at the same time ask them to sign up under your referral link, so you will earn the commission. Or, you can create a private mentoring, convince them the basic thing and offer them to join your class if he want to learn deeper.
That's why, you should have a goal or purpose before you doing something.