Well, what you said is inline with what the Binance founder also said, and you both are right to be honest, judging from what we have seen so far, it is evident that not very many people are investing in cryptocurrencies right now, and the ones who are buying or investing are focusing only on bitcoin, and those buying right now are institutions, governments, wealthy individuals like Micheal Saylor and so on, this group of categories of people are not people we can say will one day take a gamble on any Altcoin, they will always focus on bitcoin and this is why bitcoin is the only prospective cryptocurrency worthy of delivering a possible ROI even though we can't currently tell how high or at what percentage.

As for me though, while holding what I can in bitcoin, I still take a gamble on some Altcoins I am hoping will still do well, this is basically because profit from bitcoin can not give me the type of money I want even if the price doubles, which we all know is unlikely in the short term, so I still gamble on Altcoins regardless that they don't have as much prospective as Bitcoin.