That is because VLC (similarly, Kinovea, MPlayer and others tools) do not use codecs at all.
We use the FFMPeg's libavcodec library which itself implement decoding and encoding of the files. The library code is tightly integrated into the software, other softwares cannot use it. There is nothing Kinovea installs that could be used by Windows Media Player, they just work totally differently with regards to decoding files.
The FFDShow codec tries to gather the best of both worlds, it turns the libavcodec library into an installable Windows codec, so with one single piece of software you have the whole FFMPeg suite of decoding/encoding tools available to these codec based players.

