I know to some extent trading stocks is a little like gambling. A lot of things you have no idea about can happen, but there is a lot of data that can help you make an educated guess. Even then a lot of unforeseen factors move a stock price.
Crypto investing seems a lot more like straight up gambling, where there isn’t a ton to go on. Even less to go on than investing in a regular currency, which isn’t very mainstream.
The timing of the trade mostly author's gut feel that bitcoin will soon transition to a seller market as everyone who wants to buy bitcoin will already have one.
Puts being cheap is also a subjective measure. Author might be looking at past prices and making the bet. He isn't looking at greeks at all.