basically portfolio in altcoins is a dumb idea because you want your portfolio to be diverse whereas when you invest in multiple altcoins they all move together. for example when bitcoin drops they all get murdered! so what is the point of having them?
Thing is you are thought by the public diversify your portfolio, because when you diversify it what you are basically doing is you are moving towards "more secure" but this doesn't mean that you are going to gain much. It is hard to find the great coin out there, but when you find some you should put most of the money there because if it turns out to be good choice you can get huge returns. Although since this is all high risk investment only put money in you are comfortable losing. At the beginning you don't want to diversify much maybe you do in future if you have nice portion of money.
i completely agree with the earning part. one of the biggest mistakes that you can make is investing in a lot of coins and making a small amount of profit because of doing that. and also losing a lot of money because you have a lot of coins that may drop all at once and you can't control things that way.
but i disagree with saying it is reducing risk. i believe it actually increases your risk because you are not even diversifying. the word is misused here. you are diversifying if you buy gold or other unrelated assets not something that is completely related to bitcoin price to a point where it relies on it.