Maybe, but "a community that really valued anonymous posting" is likely to be defined by this value. The first "problem" is that likely use cases are users/comments/topics that aren't allowed elsewhere. So.. that community will tend to be a haven for whatever content other sites have actively ejected.

That doesn't make it impossible to have anonymous accounts, but it is a high tradeoff decision and likely a defining one.

I think it's more applicable for sites that have somewhat more objective and/or legible goals. Wiki-ish sites, for example. If there's a lot of free form discussion... anonymity is probably a bad decision for the site owner.