Diversification is the way to minimize the risks and optimize the profits. But we must be careful to diversify assets. Kindly avoid to diversify on random coins, especially unknown new coins. Better to diversify to trusted coins.
Diversifying our capital in trading or in investment, is important because it's risky to "put all eggs in one basket", but if we put many things in one basket, it won't be good for our capital management.
Choosing what eggs to put in our basket is important. In cryptocurrency market, Bitcoin is the best egg to put in, the next good egg is Ethereum. It's enough if you no longer want to take bigger risk by adding more eggs to your basket. In reality people are greedy and they don't stop here, many of them ignore Bitcoin and Ethereum, but diversifying their capital to other altcoins and focus in new altcoins.
They need time in the market, and experience loss with altcoins, to realize how risky altcoins are.
This is a mental side. Mature people must have these. Patience, calm, smart, and wise are some traits to be possessed. That's why a trader should be a mature person.
You can be a mature person beyond trading but in this volatile market, a mature person can be a failed trader. Because trading requires personal traits that are hard to achieve and you can be mature, succeeded in other fields but when it comes to trading, it's different field with different challenge.
If you can not surpass challenges in trading, because you don't have these important personal traits, you will fail in trading, and it is not because you are not mature enough.