Remove "Move to Dropbox" menu from Finder context menu
If you go to Preferences -> Extensions -> Finder, you will see the Finder extension that you can enable/disable and you can enable/disable the Finder extension from the Dropbox app itself.

Unfortunately I don't believe you can simply remove the one option but rather it's an all-or-nothing scenario based on the extension itself. Well, at least until Dropbox makes some improvements.