They are steering users away from non Apple apps. If a user installs Dropbox, it seems more likely that they wouldn't want to install and pay for icloud storage. If Apple wasn't benefiting from surfacing their app in front of a non Apple app, why would someone at Apple go through the trouble of setting it up that way?
They are steering users to install a system utility that integrates with Dropbox (and every other major cloud service).
Apple does not make any profit off of that system utility.
Google, on the other hand, makes the vast majority of their profit from selling ads that do indeed steer users away from the product they searched for.
I'm making an assumption here since it's been a while since I've looked at SEO, but I'd assume that page rank in this case matters. Any friction at all leads to fewer conversions, which means fewer sales for Dropbox. If a less knowledgeable user downloads the Apple app instead of Dropbox in this case, there will be some portion that don't end up installing Dropbox and they may instead find their way to icloud when recommended to install it after installing files. There is no way to tell the actual impact, but I don't see how it could possibly have caused no impact. They control the market, they have a responsibility to maintain a non-amazon like image. Hopefully it was a mistake.
