True, maybe it's not needed if you intend to just use mkv movie files in "half side by side" format instead of a 3D bluray disc or iso files or do not need full use of a full 3D movie file.
We have a PS3 and realtek 1185 media players (mede8er500X2 and measy x6-one is actually for the bedroom) for our 3D passive TV. We can watch 3d movie file (like the transformers 3 HSBS or 3D MKVs na HSBS or top and bottom formats) on the 500X2 without any problem. For 3D blu ray disc, then we use the PS3.
But of course a full 3D bluray iso (a non-3D media player/nmt can not handle) should be is better than MKV formats.