Bitcoin (the blockchain you're invested in) is not TCP/IP, it's more like America Online. Huge now, but it doesn't own the sourcecode/Bitcoin protocol. Just like other service providers started using TCP/IP, other coins can use the Bitcoin protocol.
Oh no, you are confusing idea with an implementation. There were hundreds network protocol implementations, anybody can take the idea of "how do I package the data and send it over the wire", but only one is the true king; others found their niches. It applies to bitcoin perfectly - there will be only one true blockchain, and there will be many niche cryptos, but it is already impossible to dethrone bitcoin - it has rooted too deep.
AOL had nothing to do with tcp/ip or internet, it was a user-facing service built on top of the protocol. Say MtGox or coinbase.
The analogy Bitcoin/AOL is certainly better than Bitcoin/TCP/IP one. Comparing Bitcoin to TCP/IP implies that other coins (providers) can't use TCP/IP (the Bitcoin protocol).
The fact of the matter is they can and do
