You cannot opt-out of allowing staff to read your notes altogether, but you can export your data and move to another service.
If you don't need OCR and are on Mac/iOS, I have found Bear to be a great note-taking alternative to Evernote.
It includes Markdown support, code syntax highlighting (for some languages), and Evernote migration:
Support for MD and notes can be synced using iCloud.
Bear seems nice as well, hadn't heard of it before. Quite like the iOS support.
Haven't used Evernote since I moved to Quiver but will give Bear a spin as well.
It's a shame, because in all other aspects I really like Quiver.
The format is "open" and easily machine readable (it's just XML really).
Too many times I use Evernote as a dump of everything and end up with ideas, email addresses, random names for people/services/brands/wtv, book/movie/music titles all in the same note that I then need each into their correct notebook and note at a later time. The problem is that there is never a good later time.