Ok, to be fair, MST3K had like 2 soundtrack albums, Clowns in the Sky I and Clowns in the Sky II. But why couldn't they release a soundtrack to the feature film, Mystery Science Theater 3000: The Movie?
Here are a few examples which I've extracted from the 5.1 mix of the movie:
https://m.youtube.com/watch?v=U88nMD3tgyw - Main Titles
https://m.youtube.com/watch?v=NHAgqbd5LN0 - We Got Movie Sign!