I don't mind but the problem is, if two people edit the file concurrently, Dropbox won't merge them. It will just create a copy. Cloud Storage is designed to merge changes no matter how many people work on file concurrently.
I hadn't tested and suspected something like that may happen. Just keep in mind it's possible people could hack together their own working versions of a multi-user sync.
No need to hack anything. I'm going to release server edition which will give users multi-user access without putting data into cloud storage. That will settle this matter.