Hi Christof,
Thanks for reaching out with your concern regarding the MS-ODATA spec. After inspecting section 3.2.5.1, I found that the double quotes are intentionally added as a form of escape character because the entity (whether character or string) is within an English paragraph. There are many instances in the Open Specification documents that have these double quotes within paragraphs to ensure the reader knows where said character or string begins and ends.
Feel free to reach out with additional questions or concerns.
Regards,
Kristian S
Microsoft Open Specs