Ha! Always the contrarian...but here is my take.
The FGI P&R discussion was interesting BECAUSE of the diverse opinions and topics. I liked the debate. I always felt all sides were respectful of each other. Every once in a while someone would fly in and crap all over the place. But they never lasted too long.
Your favorite political news/blog, in contrast, is far more boring because of the homogeneous opinions and hyper-focused nature of the topics (eg, all about DC politics, or all about atheism, or whatev...). Nothing but monochromatic echo chambers.
It wasn't a room for everybody, but for those who participated, er, religiously, most got something out of it. I mean, we solved a lot of problems there, over the years.
I count the P&R subforum was one of the many good things Justin accomplished with FGI back in its prime.
Why is it no longer the same? Like I've been saying for years, evolution happens all the time. Change is just hard wired into the nature of things. I'm pretty sure that's all driven by moleeds.