There are a few reasons.

Your parents are trying to protect you. That said, the older generation are not as well versed in modern ways as we are. To a flaw, your parents will always think they know better, and while most of the time this is true, they do not see the times when they do not.

Imagine a 10 year old coming to you, and explaining that you should put all your money into sand because that's the new big thing. It's understandable to be weary of something you don't know, and try protect your loved ones

Try explain it in a way they can understand and show proof, logic and risk vs reward in numbers.