Many just realize that its better to invest for long term with bitcoin rather than participating on any trading activities which provably put them on unknown situation since every short term movements people take bring them huge risk to lose money especially that market is so unpredictable or volatile.
If they doubt that bitcoin is best asset to invest then that means they don't have knowledge about bitcoin. Maybe don't try to explain bitcoin to those people who don't believe since its like you are trying to hard sell this to them but at the end they still ignore it. Much better to focus on your investment and don't take to much unnecessary attention since it will just bother you. Bitcoin is really the king no doubt for that and it always good that we have some share save for future since provably that there's huge chance for us to earn with this since holders is always the winner if we base on past profits result from people who engage with bitcoin long term investment.
Trading is high-risk, it can be anxiety-inducing and energy-draining as monitoring the market at all times can be stressful for traders especially when the market is volatile.
And it is better to invest enough to be safer and calm our minds.
Actually there are still many of them doubt bitcoin as a long-term investment, I don't even care about that the important thing is to have confidence that investing in bitcoin will be more profitable in the future then now just collect more by means of any strategy you can afford.
I won't even think about other people who don't believe, it's better to ignore people like that, maybe he will regret it later when the price is still cheap but still doesn't buy because of doubts.
The important thing is how we grow the portfolio will be better.