That’s not true. We have tons to TS files and they play just fine in media player and load just fine in Custom Cuts.
You’re confusing a couple of things. Media player is just a wrapper. What it plays and doesn’t play is controlled by Direct Show media codecs. If Windows finds a matching codec or send the video to the codec to decode the stream and return the raw data which it then renders.
There are two types of codecs, container codecs and video codecs.
TS is a container which can contain mpeg1, mpeg2, mpeg4, mpegH or any other supported video format. So when media player loads a video file the first thing it does it try to find a container codec that supports decoding TS containers. Windows direct show and media foundation layer has built in support for most common containers except for MKV (which is why MCEBuddy ships with Haali Media Splitter which adds the codec required by media player to load MKV files)
The next step to identify the codec responsible for decoding the video stream (mpeg1/2/4/H etc). Again windows has built in support through its media foundation later for most codecs except for odd ones like flash or mpegH. (Which is why MCEBuddy comes bundled with FFDShow which plays very nicely with media foundation later and Direct Show codecs to supplement what windows has and a great UI to switch between windows codecs and the FFDShow codecs)
So none of this has anything to do with media player and everything to do with how you’ve setup your system.
All issues that folks face are to with the codecs they use. We do not recommend the use of shark or k-lite of any of the codecs pack because they essentially destroy half the window media foundation system (literally they disable half the stuff and crack the registry sometimes so badly you can’t even restore it) and install codecs that aren’t compatible with the direct show framework which essentially breaks everything.
We have virtually no issues with any of our Test machine with most files and custom cuts. They are clean installs of windows with no custom codecs packs.
If you want to use custom cuts start with a clean install of windows and don’t install any codec packs unless you’re sure you need them.