I do not know why you think investing into a risky activity like Bitcoin trading is somehow better than gambling nor am I sure where "Those who do not have personal income will not be involved in gambling" fits into the scheme of investing to learn about something, but hey, to each his own.
Gambling is almost just as risky as trading, especially for trading newbies who tend to trade on emotional decisions instead on good and professional strategies. And they most definitely will do that. And they will lose their money, just the same as if they lost it in gambling.
Don't know why he is comparing, I know gambling activities will lose more than trading but both have quite high risk, it's not as easy as what he said in trading, for me it's easier to buy bitcoin and then hold it this may not have any risk at all.
What about futures trading? This will obviously be even more risky because guessing the price if it misses will lose their money, indeed beginners, for example in spot trading tend to lose more than profit they are not yet skilled especially by not being able to control emotions when the price does not match the target.
I know that gambling is bigger to lose money but you also don't ignore the risk of losing money in trading.