To the best of my knowledge the Serious Business page has always been pretty clearly defined- when characters in a work of fiction are treating an issue with far more importance than seems rational. If a stadium with several thousand seats is sold out so people can watch a children's card game tournament, well, that's because children's card games are Serious Business.
Where this trope is relevant in the development of repair protocol is that, from as early as the YKTTW stage, it was recognized that some of us were taking this whole rename thing a little too seriously. On the one hand you had individuals decrying rename efforts as sucking the heart and soul of the wiki. On the other you had folks (such as myself) that believed effective quality control was essential to giving TV Tropes any sort of meaningful credibility outside of a relatively narrow subset of nerds.
One benefit of the YKTTW stage of renaming was that this never really got too out of hand. Rename proposals were a very small minority of overall trope proposals, and the contentious ones were even less in number. So however fired up a person got over the latest iteration of the Jonas Quinn debate, the fact of the matter was on either side of that debate there would be perfectly reasonable, non-objectionable proposals for new wiki material.
The earliest issue with the trope rename forum was that this kind of pro/anti rename faction rhetoric because much stronger and much more difficult to avoid. A person clicking on the trope rename forum quite literally sees rename proposals everywhere. Now, granted, most of these were for obscure titles no one had likely heard of before, and most of these were also not actually followed through on even when consensus was established. Nevertheless, it's understandable that some people looked at the forum and thought nearly all of the wiki was up for massive modification. This created something of a feedback loop- as anti-rename individuals became more strident, pro-rename individuals also took a harder line. Much of this frustration was compounded by the fact that, in spite of the When To Rename A Trope guidelines, the exact same arguments seemed to be rehashed repeatedly. This led to a sort of rhetorical arms war, where stronger more logical arguments became increasingly necessary to move any efforts forward at all.
If all of this sounds crazy, well, it kind of was. The word "rename" had attained powerful visceral reactions from any wiki-goer who heard it. I think part of it was just the word. "Rename" is a pretty simple word, but it's seldom used in real life, so in the TV Tropes realm it managed to attain nearly mythic stature. And even if it's a simple word, the greater implications are pretty darning. By renaming something you're kind of changing its very identity.
There's plenty of Serious Business around the wiki aside from renames of course. The cause of nearly any Edit War is a result of at least one person taking a single issue far, far too seriously. The main difference is that in the wiki proper, such strong reactions are generally unusual, and most people would never even notice them unless they scoured the page histories. On any given day in the trope rename forum there is a very good chance that you can see someone taking something incredibly seriously after clicking on just the first few threads.
I suspect that this general attitude perplexes and alienates most wiki-goers and contributes to the low gross participation in trope repair protocols. I'm not sure I would have had the confidence necessary to join the trope rename forum if I hadn't been involved in the protocols from the beginning. Just as well, the after-effect of posting and editing in this environment is probably what made me feel it was necessary to start this blog in the first place.