I saw something on a friend of mine iPhone I was amazed, this guy has 3 pieces of bitcoin but he didn't look it when you look at him with mere eyes, I ask him how he has come this far, he told long ego he was seriously investing on all kinds of coins with little amount of bitcoin but then most of those coins help him to realized enough amount to buy more bitcoin because that was his primary target. He normally buys those zero value coins when they appreciates it will be enough money, and that's how he convert and swag all to bitcoin and today, he has 3 piece. Is good to be diversified in your investment, somedays something good will come out of one you don't expect.
I think your friend is very great in analyzing and making the decision to invest in Altcoin who has the potential to provide more benefits, I think he is a great person or a lucky person. Maybe there are also some coins that scorch the money.
Diversification is indeed necessary to increase the amount of probability to get more profit to potential Altcoin, like your friend's decision.
But yes you must have accuracy before actually entering your money into it, if not you just squander money and only bet on God's hopes of saving you without you knowing the causes and consequences.
It's kinda converting the profits from altcoins to Bitcoin which Bitcoin intends to have value. It's like he wants to protect his profits or capital by converting it to Bitcoin.
Your friend got point here because as you can see a lot of altcoins come and go, they are only driven by hype but Bitcoin stays and always at number one spot.
Maybe what he did was save his profits in the past from Altcoin and divert it to Bitcoin because he saw many Altcoin who had today's problems, in other words Bitcoin was the safest to store your values and wealth.