"This person" is Jason Scott, who works as the Internet Archive and also heads up Archive Team (the loose band of internet folks who race to archive sites about to go dark).
He's a digital historian; his job is to save everything he can.
Remember that next time you're red with rage because a cloud provider lost your data or a service you depended on is now bought/closed/gone.
To constructively disagree, though: I keep backups. I have a Synology NAS device that I really like. But for your average person, I have to wonder - are their digital photos really safer on their laptop than they are on Facebook? Facebook is a fairly stable company. Laptops are lost, stolen, and damaged all the time. Files are accidentally deleted. People get viruses. People forget the password to their full drive encryption. When Facebook does bite the dust, it's hard to imagine that data just disappearing - it's incredibly valuable, and in the worst case, someone would buy it just to sell it back to people. Not ideal, but it isn't lost, and you had free storage for several years anyway.
Tangentially related, this is why I shoot RAW. Not because it might give me better pictures today, but because it WILL give me better pictures in 5-10-20 years. You can take a RAW today that was shot 5 years ago and pull detail that was impossible to pull when it was shot, and that ability will only improve.
By making a technically inept strawman, it's reduced to an argument of which is more idiot proof.
The problem with idiot proof is that there's always a better idiot out there.
The argument here by the 'anti cloud' side is 'why not both?'. To argue for one side or the other exclusively is pointless.
In other words, in real world usage, the cloud is more dependable and flexible than internal IT infrastructure providers, for most businesses.
That said, there is a good philosophical argument against the cloud.
I agree, but its fundamentally simple: Always be in control of your own data, because no one else is going to be looking out for it.