That is as may be (though I'm not sure it's quite as dire as all that), but I'd argue that if it isn't true that anyone can edit and see their changes instantly then it isn't really a wiki.

That doesn't mean wikis can't have bans, require captchas, or lock pages that are frequently abused to tenured registered users, but the tooling needs to support instant updates and freedom to edit needs to be the default. Otherwise you're looking at a static site or a CMS, not a wiki.