It does have anything to do with all "playing" nice. Just how they are installed.
Shark is popular I agree. However the way it has been designed is not entirely correct. Windows 7 was a platform that works very differently from windows xp. Microsoft decided in its infinite wisdom not to allow 3rdpaty codecs to wok with WMp and WMC by
using the windows media foundation layer. Honestly the platform is darn good for most purposes.
So work around the limitations shark codecs pretty much had to destroy the foundation to get the custom codecs to work. That was a bad approach.
There is a cleanser approach now available. Use the direct show media foundation tweaked tool. It plays "nice" and disables the media foundation and allows you to use 3rd party codecs that also play nice with windows like ffdshow and also allows
you to revert / undo the changes very cleanly.