Yeah, maybe Nintendo had to give away copies of DW1 at one point, but maybe that's not a rejection of RPG's by gamers, maybe that was just a reflection on how DW1 was incredibly archaic even for an NES game by that point and some of us had already played things far superior on a technical level, even on consoles (Phantasy Star 1 and the NES port of Ultima 3, for instance). Don't get me wrong, I still bought DW1 (yeah, I never got one for free, dunno how I missed that promotion entirely) and enjoyed it, but I can see why it wasn't near the phenomenon here as it was when it hit in Japan years earlier.

And yet it still did well enough that all three NES sequels wound up getting released. Sure, the next two on the SNES never did, but there's a LOT more at work there than lack of demand. Enix had plans to release them, but the DQ5 code was so messy and buggy that it didn't pan out, and when they decided to just skip it and move on to DQ6, the company was going through major changes and wound up closing their US offices before it could come to fruition.

Another thing to consider, gaming itself is far more mainstream today than it was back in the 80's and 90's. As gaming has grown, so has the RPG genre.