Bitcoin price history is necessary for all Bitcoiners, but to be a successful holder you have to understand the price history of Bitcoin.
This will help you understand the volatility of Bitcoin.
When you know the price history of Bitcoin you will understand that there is nothing new about the fall and rise of price. Also, the history will let you know that the price always goes back up after a fall and that should help you in your effort to hold Bitcoin.
What you are saying is correct, and I completely agree with you, but you are forgetting a very important thing: the psychological aspect. You can do your researches, studies, and then you may think you are ready but then comes the dump: -20%, -40%, -60%... And not everybody is able to handle it, many people can't take it anymore and they sell at loss. Bitcoin, at the moment, is not for everybody.