Because according to him Bitcoin is a small number of people who have a lot of Bitcoin. They can easily go down on the bitcoin market if they want to.
Example: Cz. Craig wright & Michel Sailor etc.
Looking forward to the well thought out opinion of the experienced in this regard.
There are many people that are eager to invest in Bitcoin because they have been seeing results of other investors who had invested in it with profits. The door is opened to everyone to buy and hold Bitcoin for as long as they are ready to hold before selling.
What OP wants to say here is that his friend knows about bitcoin but he doesn't show interest in bitcoin due to some reasons like many risks, manipulation... and if add the title then, it can be understood that OP's friend is a fairly wealthy person. In short, many rich people show no interest in bitcoin, which is what I understand.
Many people want to invest in bitcoin but not all. Not everyone after learning about bitcoin likes it and will invest in it. This is completely normal and they all have their reasons. I also have a few friends who know about bitcoin but they never seem to be interested in it because they also have their own stable jobs.