I don’t like it either. You prompted me to look again. There is now a button in your dropbox preferences to turn off that feature. I just tested it and it appears to remove the feature or at least disable.
Thanks. I think I managed to find how to switch this off a few days ago as well. I think it’s interesting that Dropbox is trying to make their product more useful as I think their engineering on the syncing side is unparalleled but they shouldn’t make users have to opt out.