Just because Canonical did something morally dubious doesn't make it okay for Mint to do it too.
To take this to the logical conclusion, Banshee should never earn any affiliate revenue ever (unless people build from source), and the distro should take it all.
This is clearly ridiculous.
No distro removes ":help uganda" from vim, and I would argue that if only one side were to get the money, it should be Banshee.
The truth is the distros need Banshee, Banshee needs the distros. Rather than arguing over who needs who how much, split the money 50/50.