I'm no expert in this area of MC, but I think there is a long history with Connected Media. I know there were changes several releases ago. Basically, this would be the user interface for going to web-streaming sites and managing your "connected" media. There are some predefined / built-in radio station aggregates there, and you can add your own.
I don't have any good sense for how many folks use it, or how they use it. I don't use it, and for streaming any station, just manage the URLs manually.
But if you want to record a stream - there are only the two ways I've mentioned in the posted link. This would be one area of improvement. Like Shift double-clicking a link to bring open a Record Media dialog, or adding a context menu item with right-clicking a URL item.
Web stations are a little clumsy, as many use Flash, and these won't work inside MC's IE control. So the experience can be suboptimal. I'd guess JRiver has declared Connected Media to be good enough, and not much worth investing more time. All speculation on my part.