More and more sites are driven by lazily loaded content, though – for which javascript is a prerequisite. Do note that you’re excluding a significant amount of sites this way.
I'm aware of the severe limitations for this first pass. For now, the main focus is building a corpus without jumping through too many hoops. Rendering JS is both a security risk and technical lift I didn't want to start with, but it'd be a top priority once I get something that I can show to other people.