This is largely because the VSL is capable of simulating serious symphonic music with a great variety of orchestral colours and nuances. Current film music is mostly locomotive string patterns, punctuated by deafening noises and brass pads - all easily achievable and believable with even cheap libraries. That is in those instances where there is no choir belting out irrelevant latin or other phrases.
Indirectly, you can infer that if VSL can simulate Beethoven, Stravinsky, and Debussy convincingly, it can do modern film with its eyes closed. Maybe not as loud as other libraries can, as it is intended to simulate real-life orchestral playing.
There is a lot of sophisticatedly orchestrated film music these days, yes, there are some of that locomotive string patterns, ...etc. sounding scores, but on the other hand, there are a lot of very interesting scores.
I personally enjoy listening to sophisticated orchestral film scores more than traditional orchestral composers works. Which I have heard over the years. That's why I was asking why not much film/soundtrack music is being posted on this forum. Actually, I would even go one step further, and say that Orchestral Film Music is the new generation of Classical Music. It is the genre that is pushing the bounderies of Classical Music to the next level. It is very exciting to listen to, and I feel the emotional impact some of the later soundtracks bring to our ears and hearts is a very rewarding, and rich experience. With or without watching the visual media.
Cheers,
Muziksculp