Losing is part of successfully trading. If you treat losing as part of trading then you are an experienced trader.
Trading is part of our bitcoin market and losing is one key to success. With losing they will know when we get wrong decision so that it will become lesson to our self. To make sure for trading they need experience, enough time and more knowledge about bitcoin. The more you have to know the more you can earn money. A successful trading will not always success sometimes it will bring in losing.
Trading is a business, loss and profit are part of business. But yes trading loss will teach lessons how to do trading. And every loss is one good lesson for traders. Once we become a pro in trading then if we lose money in trading we will not get fear. We can handle that situation. But for new comers, it is tough to deal with this situation they may get fear when they lose money in trading
I somewhat disagree with your opinion
There is a saying which claims that it is rarely the case when people make the same mistake twice since it is typically thrice and more times. And I heavily support this view since I often notice that I'm inclined to make the same mistakes again and again (though not necessarily in trading). So I don't think that losses will teach the majority of wannabe traders. At best, they will just call it a day and get busy with something else (and that certainly won't be the worst choice)