PS. thanks for indirectly sharing a link to All The Tropes (linked author's fork of TVTropes) too; might have a poke around there.
It's also worse on tvtropes than most wikis because there is a very limited revision history on most pages (might be the weird software they use rather than admin-imposed), and anything that falls of the end of it after long enough is gone forever.
edit: How accurate is the Encyclopedia Dramatica article on TVT? I normally avoid ED, but I gave in this time because it seems to be pretty comprehensive. edit 2: I found this blog: http://tvtropeshistory.blogspot.com/ Obviously it's hard to verify histories like these, but it seems pretty in-depth.
* The Google Incident [1] explains first-hand why TV Tropes adopted tighter guidelines against sexual fan fiction, from which several forks were created as reaction.
* The fork All The Tropes explains how they are different[2], and why they made the fork [3].
* This recent discussion at MetaFilter have lots of details and reaction from the community [4].
* These are the most juicy discussions at TV Tropes itself: [5] [6]
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[1] https://allthetropes.orain.org/wiki/The_Google_Incident
[2] https://allthetropes.orain.org/wiki/All_The_Tropes:Who_we_ar...
[3] https://allthetropes.orain.org/wiki/All_The_Tropes:Why_Fork_...
[4] http://www.metafilter.com/138391/You-are-in-yet-another-maze...
[5] http://tvtropes.org/pmwiki/posts.php?discussion=13850739750A...
[6] http://tvtropes.org/pmwiki/posts.php?discussion=13426240890A...
Stick it on a few linode or AWS VPSes and add some backend code to bring in new ones as load goes up, maybe with physical servers for database backend. Switch to nginx if it doesn't use it already (can't remember (edit: yep, using Apache; also seems to only be on a single IP, hosted by ServerBeach)), add memcached, perhaps put the whole thing behind cloudflare, and problem solved.
I'll also note that the forums make up most of the traffic of the site, and that's the one place you can turn off adverts for free. The wiki supports the core product, which is apparently the forums.