Well, that's an idiotic statement by Gabeaul. The ONLY viable use today for WMC is the DVR functionality. It can't stream worth a crap, and in it's native form (sans Media Browser or Plex), it sucks for local/network media playback. As a DVR, it's extremely good and the only real player in the cablecard area.
If anybody really uses the HTPC to watch any physical media, they certainly use it for blu-ray by now, which means they bought a blu-ray software player. This means that WMC has nothing to do with DVD playback, because they would almost certainly use the same player for DVD as for blu-ray! And who the hell watches regular DVD's anymore? MWC can't even play the dominant disc format that has now been out for almost a decade.