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 )
Th forking (or absence of it) does not effect Bitcoin's supply. At best, you can consider it as a "gift" to all bitcoin holders, which will increase the overall worth. It in no way impacts the overall supply of 21 Mn, which is set in stone.
That is precisely my point. I create "Bitcoin2" by forking. Then I create "Bitcoin3" and so on and so on.
In reality what I am doing is issuing more Bitcoin. That I call it a different name does not change the reality.
You have a flawed understanding of forks. None of the recent forks have been accepted as Bitcoin2, and none of them ever will be. They're considered as altcoins which are basically using Bitcoin's branding to their advantage. Coins are only as valuable as people deem them to be, and no one would support a coin that just aims to increase supply. Why increase the supply if Bitcoin is infinitely divisible anyway? There will only be one Bitcoin. Bitcoin Cash and Bitcoin Gold are altcoins, much like Litecoin or Ethereum.