Yes but once you do have an account, I would say its the best file sync platform available. It never downloads the files until you click on them however it always displays all your files. No initial sync time and no taking up space for files you will never use. Its also safer because the majority of your files are never stored locally.

Do you realize there are legitimate cases where you don't want to use a MS account?

Ex. When you use a domain account managed by someone else (ex. your employer or school)