The argument is again and again that the value of Bitcoin will increase because supply is limited to 21 million. But this is quite simply wrong. Every time Bitcoin is forked that is in real terms an expansion of the Bitcoin currency beyond 21 million. To some degree the same is true of alternative crypto currencies which will flood the market. There is already more than 1000 cryptocurrencues (
https://en.wikipedia.org/wiki/List_of_cryptocurrencies )
It seems that you have an assumption like this, for example Bitcoin is the first bitcoin, Litecoin is the second bitcoin, Namecoin is the third bitcoin and so on blah blah blah. Very reasonable indeed if someone has such an opinion, because maybe you also think, that Alt-Coin was created to extend the age of bitcoin or to slow down the supply of bitcoin from running out. It seems that this is a narrow mind that means not having a firm stance. I think even though Satoshi Nakamoto will create more new coins, but the power of crypto market law will still apply because the core strength of each cryptocurrency will remain with its users.