Wimp seems to have no official API to use their service, while Qobuz has one.
On the other hand, Qobus seems to demand a specific way of showing things to the user (showing recommandations, "My Music", new stuff...) in a manner that may not be easy to integrate into RuneUI. I don't know about equivalent requirements for Wimp.
To see what a usable integration of Qobuz looks like, see the Qobuz add-on for XBMC/Kodi. It works well but is not the prettiest thing on Earth.
From the Kodi forum:
Whatever the Wimp support staff and others said on twitter, it's wrong. They do not have an open api.
The api is closed and for professional business partners only, so I have no idea why they keep telling people publicly they have an api. This and no open source means wimp will never be available in xbmc. Better switch to spotify or rdio if you really want a streaming service in xbmc.