You're straw-manning here. Not conceding isn't the same thing as denying. To not concede something, one just has to omit the concession from one's writing.

I'm not sure why anyone would expect a post about trying to attract academics to LW to mention that academia has some advantages over LW. It's just not relevant to the subject. The fact that MIRI has been increasingly making use of academic channels is an implicit concession that they have advantages.

Anyway, some web channels where academics hang out: ...

Ok, yes, there are web-based academic channels. StackExchange is even a good contender for highest-quality relatively-general-interest forum on the web.

(Cracked? Are you kidding?)