Take it easy dude. In time, they will realize that they're all wrong about bitcoin. They just lack the knowledge about it that's why they often blame bitcoin whenever their investments comes to trouble. Patience is the key to success when it comes to investing in cryptocurrency. If a certain person isn't patient enough, this person will eventually panic whenever bitcoin's price go down.
Yes in the end of the day they are still the one who will regret it not believing on it on the first place that they knew bitcoin. Surely time will come that they will part of our community who was earning bitcoin and soon they will also fight for it to those people who will say that bitcoin was just scam.