I think the best way to shut up bitcoin haters is to prove that you are earning on bitcoin. When I was starting at bitcoin, there are a lot of negative comments from my friends and they were always telling me to be cautious. Only a few of them supported me and those people are investing on bitcoin as well. They are earning enough money for their needs and they never regret investing on bitcoin even if the price goes up and down.
I total agree. Best way to shut up them is proving that you can earning on bitcoin. First time i dont believe in. But some of my friends, they buy house, buy car and get rich from it.
admittedly, investing in bitcoin is many risk. But if you have good mentor any good strategy and lucky. You will earn money from it .