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.
For the best way to shut the mouth of the haters isbto prove them that bitcoin is not a scam nor illegal, I will tell them that bitcoin id a job that, we can earn a lot of money after a few months or a year because in bitcoin, you will surely earned money, bitcoin is worth if waiting because it trustworthy and it surely that your account is safe amd secured, and lastly, there is a lit of people who can prove that bitcoin is real.