It's not like Darkstalkers was ever a must play fighter anyway. It took the conventions of other more popular games, but threw in a cheesy monster theme. (i mean the theme was cheesy monsters, not that the concept was cheesy) Not what most would call ground breaking even in the old arcade days. Let alone now.
This is the kind of game that should have come out around EVO. When fighter fans are really jazzed up on the very notion of fighters to begin with. Dropping it, barely announced or promoted, at random... I mean what do you expect? Not every fighter is going to set the world ablaze.