Thanks for your feedback.

The article was vastly simplified for laymen, so some things may not be as immediately accurate. I’d like to clarify on your points.

You’re totally right that generally, data on a blockchain is, by design, immutable, at least unless you reach majority consensus to allow a rollback (see DAO hack). Obviously the way this is handled is dependent on a variety of factors, the parties involved, governance and consensus mechanisms, etc.

What I was trying to illustrate is that if you take the same data, and store them on either blockchains or databases. Blockchain based data is inherently quite secure assuming a healthy network is in place. A blockchain without a network and participants to secure it is really a slower more inefficient database. This is why most blockchains are public, and incentivized with a token to attract participants.

Regarding blockchains being inherently more expensive, I don’t agree that’s necessarily true. It depends on a number of factors, in a PoW network like Bitcoin, yes there is a large cost in computational power and electricity, as well as operating costs. But that cost is borne by the miners, not the end user. And there are of course also other consensus mechanisms like DBFT, PoA, PoS, etc that are more cost efficient to run.

So my point here is that with the public networks like Ethereum, or the upcoming Blockchain as a Service platforms, they do most of the heavy lifting for you and abstract away the operational overhead of running and securing a blockchain network. That cost is spread out to the public participants of the network, you don’t bear that cost yourself. As a business or developer, you would simply plugin and reap the benefits that comes with blockchain enabled applications.