This isn't going to be an insightful post, more of a rant that I am sure many people who invest into cryptocurrencies and have an understanding of blockchain technology is will probably relate to.
I need to get this off my chest, because I've had several run-ins recently with people confusing blockchain and cryptocurrency with one another.
Stop confusing cryptocurrency and blockchain
They are not the same thing. Repeat after me: Blockchain and cryptocurrency are not the same.
Initially the concept of the blockchain was to facilitate, authorise and keep a record of transfers of Bitcoin and other currencies.
The explanation of what blockchain technology is, is actually rather simple. A blockchain is a shared database of entries (whether it be transactions or anything else) that are confirmed and encrypted.
Going one step further, this record of transactions is tamper-proof and publicly visible. While the concept of blockchain was initially to securely create, distribute and track the issuance of virtual currencies, it is now being used in many different facets (digitising assets, secure transfers, ownership).
The benefits of blockchain are effectively being able to replace paper. The concept of owning something was once done on paper, but in the future it'll be done on some kind of blockchain where the asset owner simply has a private key.
So, while cryptocurrencies leverage blockchain technology to handle/confirm transactions and prove who owns what, cryptocurrencies do NOT equal blockchain.
You missed the biggest part though which is that they are connected. You can't have the most secure, most decentralized, and what will eventually be the fastest blockchain without Bitcoin. If one entity owned the blockchain it would really just be a database at that point.
I didn't want to get into the specifics, but the future of blockchain technology is going to be less about virtual currencies and more about creating secured decentralised databases for things like voting, moving money (which is already digital anyway). What Bitcoin did was beautiful: they incentivised validation, do this work and maintain the blockchain infrastructure in exchange for some coins which are worth real money.
I think there are advancements being made that allow for a decentralised blockchain to exist without needing a whole lot of validators (nodes) to maintain the network. But for now, you are right: cryptocurrency is keeping blockchains alive.
Exactly, like what Ripple has done, to the disdain of many.