well, you can't blame anyone that outrightly assume that when one is talking about diversification especially if the person is new to the whole bitcoin ecosystem that the analogy is always on investing in some altcoin probably because the individual is trying to be smart or thinks that by so doing, he can play too safe while exposing himself to the risk that comes with investing in some altcoin. it is the same way people have made use of the term crypto while referring to bitcoin and altcoin thereby sending a wrong impression that tend to suggest that bitcoin is just one of the cryptos and not a different entity that has it potential that is unmashed with the idea that is painted by show shallow gamblers out there.

those that assume that it is too late to invest in bitcoin are the ones advocating for diversification of one's investment portfolio as a way of minimizing risk because they likely think that bitcoin has gone past that stage that going all into it looks really profitable. the fact still remains that even though bitcoin is getting less volatile, the chancing of it going down below certain value is becoming almost impossible and that is the main reason that makes it an asset that is worth investing into because it is even less risky, we have seen how bitcoin has grown consistently and how much it can still grow in the future and even though it might not shoot too high in a twinkle of an eye, it ability to growing to new ATH after new ATH and the fact that we can invest using DCA regardless of the price makes it worth buying both at the present and even in the future.