I remember a friend making the argument that Altcoins can overcome Bitcoin because they can incorporate additional features or technologies that bitcoin does not offer, to which I responded with the view that there are many factors that might make it impossible for an Altcoin to overcome bitcoin.
That is true, however so far none of them have introduced any new technologies which could be superior to Bitcoin somehow. In fact, altcoins just pretend to have innovative features, which in the end mean nothing on the practice for the average user. It's all about speculation and short term gains. They appeal to marketing, so some investors can get persuaded believing these altcoins have indeed potential to become more popular than Bitcoin. It's especially a common phenomeon among newbies, but once they get more experienced and used to this industry, they will understand Bitcoin is unbeatable.