I should add I am not saying JRPG's are bad now, I can't judge that but as a newcomer to the genre with FF13 being my first I think the company has been successful in enticing new gamers to the franchise because I loved that game, this may be why its sold that well & reversed the decline the franchise saw in the west, its attracted new consumers. As far as I remember its reviews were lower than expected which crushed any hype the game had.
However apart from it no JRPG has sold well, so its an exception to the rule.