Not only that, but it also misses the point in the original context. Missing an inotify equivalent can be a handicap for a number of different applications. Whether kqueue is an acceptable alternative sounds like it's worthy of a separate discussion.
I use Tarsnap and Dropbox. They aren't the same at all:
* You run Tarsnap whenever you want to push changes; Dropbox automatically pushes changes.
* Tarsnap is for 'real' computers only; Dropbox runs on my phone (which is very useful for photos, among other things).
* Tarsnap is billed by usage (at a very small amount); Dropbox has a free tier.
* Tarsnap doesn't have a natural sharing usecase; Dropbox does.
* Fundamentally, Tarsnap is backup, and Dropbox is sync. They are two different things. Not to mention that Tarsnap is also supported just fine on Linux.
That's a backup solution which you can also run on Linux without an issue. Dropbox is more for collaboration. It's often the only tool in its class used by smaller publishers or marketing companies. They don't have an ftp or webdav server. And it sure beats emailing files around.
What a horribly arrogant and conceited thing to say.