You're not wrong, but I think you're missing his key point, which is that a forum for free thought simply isn't if it's policed by content moderators around a set of culture rules, no matter how high-minded the intentions. Now for sure, WP has moderators, and they are human, but they're pretty tightly bound to enforce only the rules of admission. They're not vested with the power and mission to censor opinions deemed odious or disharmonious. I'm sure abuses happen and the slope is slippery, but moderators tend to respond to conflict there. Not predefine and block it's alleged precursors.
>a forum for free thought>if it [isn't] policed by content moderators around a set of culture rules
The rules are mostly invisible to us because we are surrounded with, and submersed in, this very culture 24/7.
To get written up in Wikipedia one must first get published in a reliable source. This mostly means a journal or "books published by respected publishing houses" (full list: [1]). The publishing is the gatekeeper here; the wikipedia moderators are a secondary consideration.
This does indeed silence out a priori (i.e., censors) ideas that are culturally unpopular or frowned upon or just held by small number of individuals. To avoid muddling the argument with hot button issues, here's a very mild and barely objectionable example: picoLisp, a modern interpreted programming language with dynamic scoping. Having it written up, and then kept, in Wikipedia is an uphill struggle spanning years, and with sad reversals & losses. And that's with ideas that are only mildly unpopular.
Again, Wikipedia's utility is clear and recognized. Let's just not mix it up with a public square.
