Reminds me of the infamous dropbox comment :)
1. Why would I want to host my sensitive data on someone else's servers instead of my own servers and storage hardware?
2. Why shouldn't someone have a physical media backup for time-urgent, sensitive files? Last I was in school, if I had a final presentation, I would absolutely store it both on a hypothetical cloud storage volume and a backup on a thumb drive. If I were still in school today I'd do the same thing. Would you really risk your final course grade on the possibility that Dropbox is down when you are up to present? And nevermind the arbitrary and random account suspensions that all SaaS providers are infamous for (looking at you, Google).
Your points are valid ones about data privacy, and redundancy of important data. And how Joe public doesn't seem to notice those.
The original infamous comment dismissed a tool that made a task easier for regular users because the server nerd says: "I can build it in my shed out of rsync and bash using a server I maintain, why should I use this?".