OK, then there's two things to complain about:
1. Why the change? I can live with multiple feeds, but preferred a single master. If C9 adds a new forum, I'm not likely to catch that, since I don't go to the C9 website directly very often.
2. This HAS to be made visible on the web. Embedded meta tags work great for auto-discovery, but not all users understand that, and even some who do can become confused when there's one visible RSS icon that doesn't subscribe to what's being viewed. After all, I've coded the darn tags more times than I can count, and I still didn't think to check for them in this case. Bad web design.
Thanks, though. I'll start subscribing to the sub-feeds for now. Hopefully my first complaint will be addresed, though, so I can go back to subscribing to one feed.