When you wrote this post did you realize that that is basically what Bioware did and got famous doing?
When you wrote this post did you realize why you used the past tense? It was a different era with a different gaming audience with different expectations.
As time passes the audience for a deep, intricate RPG is shrinking both relatively and probably absolutely. With the explosion of the lightweight gamer audience there's a growing opportunity cost to producing such a title because it holds so little appeal for this new demographic. Further, the core audience of such RPGs is gradually growing smaller on it's own as they get older and have more to do with their lives and less time to devote to such a game, even if they still want to.
Additionally, the amount of development (read: cost) that goes into a 'true' RPG I would think is quite staggering. Dragon Age was released in November 2009, first announced in summer 2004, and presumably in development for months or even years prior to that. So, conservatively, that's at least 5 years worth of manpower, computational power, debugging, all these resources that goes into a game are occupied. Not to mention it requires a lot of resources other games dont; huge amounts of voice acting, story writing, lore writing, extensive combing for more than just bugs; but continuity and balance as well. All for a game that did sell well, but compared to some other high profile titles, it only sold a half or a third as well and they didn't take half a decade to produce.
At some point, as businessmen, risk v reward has to come into play. As much as I trust Bioware to put out good work, I don't trust the consumer to always reward it, especially as the market becomes ever more saturated and the competition for the gamers' wallet is ever more fierce.
I don't think Bioware should abandon the cornerstone of their legacy, their RPGs (I loved Dragon Age and NWN devoutly), but I think it's foolish to ask them to do nothing but RPG after RPG after RPG when it lacks appeal to so much of the market and arguably puts them at risk in the long run.
And there are such things as good action games.