I think that CO dominates because it combines ease of entry with ease of performance. I don't shoot that division, and I don't have a dog in this fight, but I am curious.
I understand how a shooter with a dotted-nine would become interested in 2011 platforms. The 2011 potentially represents the easiest-shooting dotted and noncomped 9mm out there. If there's a "problem", I think it's from the shooters who started with more modern dotted 9mms, and who have now become 2011 enthusiasts. Their "old" gun was CO-competitive, but now they still want to compete, and with their new gun, that doesn't fit into any divisions, but appears closest to CO.
I like L10 and Open Minor.... so I'm already a weirdo, but I do think that there could be something like Production, Production Optics, Modified, and Open. Production and Production Optics could be pretty well what they sound like, with greater size and weight restrictions, 10 or 15 round capacity, no magwells, etc. Open being open, and a newly-reintroduced Modified could have some set of features like slide-ride optics, 140mm magazines, and a more generous size/weight budget than Production/Production-Optics. I'd even be interested in seeing what would happen if shooters could declare Major with .40/10mm.