Larry - I vaguely remember us having this conversation somewhere before! This Rosen passage is interesting, and I appreciate you sharing it, because although I've read various bits of Rosen, I'd forgotten this...I admire his playing greatly, and indeed - anyone who has listened/played through Bach's keyboard music notices the clever disguise of various entrances of the fugue subject (if that's not too contradictory!). But anyone with even a passing familiarity can't fail to notice also the instances in which he sets up those entrances, and makes them very obvious. This is what puzzles me about Rosen's argument...you can't miss either instance of fugal craft (disguise or highlight). Which shouldn't be surprising, given that Bach has so much fun with that form/technique...
I also think the observation that the player's enjoyment is central is key. Of course it's totally fine for people not to enjoy Gould's interpretation, but he's doing 'his thing' with the dots on the page, and I can't help but feel that this is totally in the spirit. I forget - is it in the inscription to the partitas where Bach says something along the lines of them being 'for music lovers to refresh their spirits' or some such? That seems fairly permissive to me!