You are absolutely correct the best way to go about Bitcoin is to buy and hold for a long period of time but because of impatient and the quest to get rich quick make people indulge themselves into trading and gambling Bitcoin which is very risky and not advisable for someone with little fund or one who's new. I disagree with this your statement " Bitcoin is not a tradable coin to make profit", when you say something is not tradable it means that particular thing can not be trade right? But we all know that there are people who are trading Bitcoin as we speak so that means you are wrong about that..., Perhaps you should said that Bitcoin is not worth to be traded though some people make profit in trading Bitcoin but everything has principle on how to go about it of which trading Bitcoin is little or not part of the principle of how to go about..., that is why the possibility of making loss is very big and the earlier we know this the better for us.
Trading and gambling are complementary to each other. I think if someone wants to gamble, he can gamble with everything. Gambling with Bitcoin is not impossible. But whether you gain or lose everything will determine your fate. Most people in the world have lost from gambling and a small number of people have gained from gambling. But my comment is that their wealth is not enjoyable. Because gambling is illegal at every level and no one can live happily with illegal wealth.
If you have the money, you can earn profits by investing (if you can hold it for a long time) without having to indulge in gambling. Maybe you will not be very satisfied with the profit from the investment. But remember that even small wealth of righteous path can bring satisfaction in your life. I am not guaranteed that the profit earned from Bitcoin investment is legitimate or not. But I consider long-term bitcoin investing as business and business is always legitimate. So I would say for all, it may be better to plan business through investment rather than indulging in gambling like trading.