Now that's an interesting phenomenon I hadn't thought about before. There's been a lot of discussion recently about tech companies removing/blocking content they do not agree with. In most cases (racism, hate-speach, etc) this seems pretty well justified as it helps keep these people from rallying together, but I never thought about those boards being a sort of trap crop [1] for the internet, keeping the pests distracted and away from the areas the rest of us enjoy.
They just binned /r/t_d entirely, and, in my opinion, that IS an agree/disagree decision. The same folks will be back with the same content under a different sub, but I doubt they spend enough to punch through again this time. I think, given their success last time around, that the price will be much higher.
Then again, what do I know? I was a pretty avid user at one time. Now I block the whole site and everything related. At this point, there's very little useful content left. It's basically just a giant portal for porn, and with 2 young boys in the house, and no way to filter it, I don't want it on my network. If they'd offer a DNS-based "safe" mode, like search engines, I'd open it back up.
It wasn’t just random, I noticed a major shift leading up to the 2008 election. Reddit’s decision to lock some vocally awful subreddits (/r/politics /r/atheism /uspolitics etc) made the homepage a gaggle of Obama & anti-religious rhetoric rather than anything compelling.