Only small % of my store-bought 3D movies available

Over the years I have bought hundreds of 3D movies on blu-ray discs and identified Apple as my choice of download/playback venue. Among these, 27 show up in my AVP's AppleTV app as available 3D movies that I can watch free. This is a very small percent of the 3D movies I bought, which is disappointing. Anyone else experience this sort of disappointment? Is there anything at present that can be done so that more of my purchased 3D movies are available for me to watch in my AVP?