Why is it stupid when it has proven itself to be the best investment opportunity of my lifetime?
Explain to me the mechanic in Bitcoin that gives it a positive expected value? pro tip: there isn't.
When you buy Bitcoin you are essentially gambling on the price, its gambling not investing. There is nothing "magic" in Bitcoin that causes it to increase in price.
Any stock you buy is gambling as well because no one on this earth knows if the price will be higher in the future.