They actually use a public macOS API for those Finder icons. It seems like there's no reason at all they needed to do this. It's really shitty.
Even worse!
Fortunately their service is now a commodity (as Jobs told them when they demoed for him, they are simply a feature). I have always preferred Drobox just because it seemed the simplest (and they supported Linux). But switching just takes a short time to copy my files to one of their competitors.
I prepaid for a year's Dropbox service. I wonder how much luck I will have getting a refund on the unused amount.
I wonder why they chose to gratuitously be assholes?
I've been using iCloud Drive more ever since the Dropbox kernel extension. Dropbox had also started going wild with indexing, causing battery drain.
I guess with this, it's time to switch over for good.
I guess that's it for Dropbox for me. Though as the author says, they're not going to care.