the user profile of the 3DS might be another factor, from things like Revelations 2 not being considered as a 3DS project it seems reasonable that they've decided its demographic might not align with RE's.
I think Revelations 2 not being released on 3ds was more about the game being too advanced technically than there not being an audience for the game on the handheld. Rev1 was designed with 3ds in mind, so it has small locations (either small rooms or tight corridors) and often loadings. Rev2, on the other hand, has a lot of open locations (e.g. the forest in chapter 1, the village in chapter 2) and advanced lighting. Just look at how many sacrifices they had to do to port the game to Vita, which is, hardware wise, a superior mobile device; and yet the game still has framerate problems.