I'll give you that before other good rpgs existed, D&D was obviously the best choice for non adventuring games, simply because there weren't any other options. It's pretty safe to say D&D hasn't been the best choice for at least 15 or 20 years though.
Though I didn't say D&D couldn't be the sort of game you can do any type of game with. I just said it wouldn't be. I'll also say that it shouldn't be. D&D is about pillaging dungeons, fighting dragons, and the like. Always has been, always will be. Don't get me wrong, you can tell great stories with D&D. It's just that those stories should be about pillaging dungeons and fighting dragons. If you want to tell stories that aren't at all like that, you probably should be playing a different game, and it's unreasonable to expect D&D to sacrifice it's clearly indicated specialty in order to serve your niche.
Fair enough. There may be better games out there that would serve the RP better. But we have played DnD for ages, and we had RP when we started, and still do. And it is true, while we do have spy adventures and merchant adventures, we do also continue to pillage dungeons and kill dragons.
Reckon we will stick with it.