There are two questions one should think through.
1. Will Bitcoin become a long-term trusted store of value?
Whether one should invest in bitcoin or not depends on whether you think Bitcoin will become a long-term trusted store of value.
If it does become a long-term trusted store of value, BTC should trade around $2,000,000 a coin (depending on how many coins are lost and are actually in circulation). That is over 100x the price of where BTC is today.
If BTC does not become a long-term trusted store of value, its likely price will be close to zero (unless it becomes a "cool" collectible... which is a possibility).
So if you think BTC has a 10% chance of becoming a long-term trusted store of value, it is a good investment with a nice expected return. It is still very risky but professional investors should invest some small portion of their portfolio in this case.
If you think BTC has a 1% chance of becoming a long-term trusted store of value, you should not invest.
If you think BTC has a 0.001% chance of becoming a long-term trusted store of value, you might consider a short.
2. Bitcoin is a religion... how good are the evangelists?
Like all stores of value and collectibles, Bitcoin is a religion. It is like gold or a Rembrandt painting... it has no cash flows so its value is only what others think it should be.
And like all religions, Bitcoin has evangelists and early disciples.
Bitcoin has a few things going for it in this regard:
The savior, Satoshi Nakamoto, is unknown and potentially not alive anymore. So we can only attribute wonderful things to Satoshi and cannot see her/his faults. If Satoshi Nakamoto eventually becomes known, it will make it harder for Bitcoin to become a true religion and this harder to become a long-term store of value.
Early bitcoin disciples and enthusiasts are super smart, great at marketing, and mostly were already very wealthy before bitcoin. There are about 1000 people that were very early public Bitcoin backers... at least 50 of whom were already worth over $100 million before they got into Bitcoin (and a few were billionaires). These people are incredible connected, smart, media savvy, good at PR, and tapped into the world of finance (some run large financial institutions). They are "rebels" in a sense but they are also very much part of the establishment. They have the ability to help get Bitcoin to go mainstream.
Should you invest in Bitcoin?
I'm not going to give advice on that. In even the best-case scenario, Bitcoin is incredibly risky... so if you do invest, you should go in expecting to lose all of it.
