Well I'm not sure we need to consider merely logically possible minds, and it's logically possible that non-human minds are physically impossible.
Only in the sense that it logically possible that travel to Mars is physically impossible. The wording is deceptive.
Less Wrong is extremely intimidating to newcomers and as pointed out by Academian something that would help is a document in FAQ form intended for newcomers. Later we can decide how to best deliver that document to new Less Wrongers, but for now we can edit the existing (narrow) FAQ to make the site less scary and the standards more evident.
Go ahead and make bold edits to the FAQ wiki page or use this post to discuss possible FAQs and answers in agonizing detail.