> Didn't Bitcoin lose half its value like 6 months ago?
Let's say the following statement is true: "If X is a scam then X's price eventually goes down". That doesn't necessarily make the converse statement true: "If X's price eventually goes down then X is a scam". This is a common logical fallacy. Those two statements are logically distinct propositions and if one is true, it doesn't necessarily make the other one true as well. This is just basic logic.
Which means that bitcoin's price going down does not necessarily mean that bitcoin is a scam.
Commodities' prices can fluctuate substantially. In October 2008, oil had lost more than 50% of its value in 3 months. [1]
In August 1999, gold had lost more than 70% of its value since its all-time-high in 1980. [2]
Would you also have said at those times that oil and gold are a scam because their value had gone down significantly?
(Cue the "but oil and gold are useful" responses, obliviating the fact that cryptocurrencies such as bitcoin are extremely useful in many ways, some of them unique, and that gold's industrial/ornamental utility does not justify its historical or current price by a long shot, but rather, its utility as an investment/store of value/wealth protection/diversification asset does).
[1] https://www.nytimes.com/2008/10/17/business/worldbusiness/17...
[2] https://goldprice.org/gold-price-history.html