[fjtorres]

BAEN has thrown in non-fiction at least once before.
(Hank Reinhardt's Book of Swords; a nice read, BTW.)

They have also dabbled in MP3 audiobooks.

What are they doing? Experimenting.
It's what smart market leaders do, they look for new opportunities.
Some pan out, some don't.
In this case the authors are part of their "circle" so they gave it a shot.
Don't see much of an issue, myself.

Or, just in case: are you objecting to the *subject* of their non-fiction rather than their dabbling in non-fiction? Just checking.