That's standard-contract-chatter, not really news? There are legit reasons for this, but the actual execution is not as rough as it's phrased. In most countries you have local laws which will annul those clauses depending on the circumstances. But of course, in worst case you need to sue them for getting your right.
Unless you do something seriously illegal, I would fear accidental deletes more than this. So having backups and fallbacks, is always recommended, even if you trust the company and your behavior.
It might not be "news," but God knows how many people are actually aware of terms containing phrases such as "for any reason at any time" and "without notice".
As I mentioned here, Dropbox's Terms of Service seem reasonable. They give you a heads-up. That's the minimum I expect.
Unless you do something seriously illegal, I would fear accidental deletes more than this. So having backups and fallbacks, is always recommended, even if you trust the company and your behavior.