I am surprised people ask for people to convince them to buy BTC. NEVER let other people decide about what you should do, if you are not feeling safe with doing it, dont. You are just finding a way to be able to blame others when things go wrong.
But do you think that you will be blamed if you are convincing other people to have some decent profit if they will be able to get some good opportunities with bitcoin? Sometimes it is not bad to be selfish and that's why we are encouraging other people to know, learn and believe what is bitcoin. Because we have proof that it is real opportunity.
What you've mentioned is true. Its good to make someone learn and earn, they'll remember the good one has done. Though we have proof in hands, nothing is assured. Sometimes for our bad, the price might decrease when the one we taught gets into bitcoin usage. Better is to explain all factors, and let them decide whether to be with it or not.
It also depends on the person that we are talking to, if we are seeing their interest then we are getting excited to tell all the factors about bitcoin. But in the middle of their learning process when they are seeing the price of bitcoin to decrease very light. That's making them discourage and stops with bitcoin but when they see again that the price increases they will be active again, I just can't understand those type of people.