Campbell
Relaxed Intensity
I agree, most of those are crunchy. It's only a list of a half dozen out of a few hundred releases though. Not that I'm saying there aren't plenty more.
I wonder if rules heavy stuff lends itself to bigger tent pole releases? It tends to - as you point out - lend itself to physically larger products, although not exclusively so. I would guess that the development time is longer, with more moving parts.
I was mostly considering the question from the view of gamer mind share and overall market share. I do think that you are more apt to find simpler systems being released from small press operations because complex systems require significant resources if you going to execute them well. They are more difficult to design and test. I'd also hazard that burgeoning designers who have a head for crunch tend to focus on creating material for existing systems first, given the scope of freelance opportunities available from major publishers.