Diversification is also for peasants who anticipate failure and have no confidence in themselves. Most dont even understand that holding different altcoins doesnt count as diversification.
You're a total nuts if you diversify your coins in shitcoins but if you hold at least top 5 in CMC then I can tell you're doing good.
You're only minimizing profits and maximizing exposure to risks by holding 10+ coins and you look like a moron when you're holding 15+ coins.
It's not you're minimizing your profit but we just see the other potential coins that might give us good profit that we might can't get in holding just one coin.
Yet of course, just hold variety of coins that you think you can monitor so you won't miss anything.