This has been a long-standing thing with them - some years back there was some stink about the forced Dropbox branding in the Finder (which we now see is related to this). Many people (including me) found it rude that it insists on adding useless widgets, badging icons and inserting crap in the Finder sidebar. For whatever reason, Dropbox (the corporation) apparently believes that junk to be important enough to their business to disregard what the owner of the machine wants, and now we see the lengths they go through to force themselves on the user.

I used to simply consider Dropbox rude enough to make me not want to use it. Now that I see the company is actively going out of their way to break the intended function of security-related OS components, I now consider Dropbox malware and will begin warning others about the company.