Should there be only one? One crypto, to rule them all?
This is the idea behind the maximalist philosophy.
On the other hand, there is freedom.
A change in perspective
See, the blockchain is not just a data structure. It is actually a replicator in the Dawkins' Selfish Gene sense. It can also be seen as a creature living in the world of zeros and ones. The blockchain is a genome and could it be that the addresses in it are the genes?
To say there should only be one blockchain is like saying there should only be one species. Who are we to judge? Why should there be only Homo Sapiens? Why not Proteus Anguinus?

I know Dr. Metcalfe wants maximalism. His law states that the value of a communication system is proportional to the square of the number of nodes in the network. Applied to crypto, this means that a blockchain is worth twice as much as this same blockchain divided into two. Imagine then how much is lost when there are thousands of blockchains in the wild.
This is the greedy approach. But think about it - in the world of cryptos we, the humans, are gods. We created them and they serve us. Though in a way we serve them to - helping them replicate. I find it fascinating that there exists an entire ecosystem of thriving blockchains.
Keep an eye on our creations.