Your friend saying are not at all bad. It cames true in some peoples life. Although there is no guarantee that it will happen to everyone, but I think almost all new investors face it, face losses in the beginning and after gaining experience through those losses, they understand the basic trading strategy. This happened in my own life too.In the beginning my investment journey started with altcoin investment but the experience of that investment was very bad. I am still bearing that loss. Moreover, when the market was in a bullrun, I invested in Bitcoin and I am currently holding that fund for recovery. However, I have understood one thing inside that if you want to invest in Bitcoin, you have to do it for long-term. I am currently following this strategy and making a monthly investment in Bitcoin using the dca method.
Perhaps you are right, many people lose something at first, this becomes an integral part of gaining experience in investing. And also, after the first failures, there will be those who decide to stop there, and will be those who continue will gain experience and will have a chance to make a profit in further investments. I am of the opinion that long term investing can only be applied to Bitcoin, if you want to trade altcoins it may be appropriate, but I would not hold them for the long term.