Maybe the fans of the old games are not the game target anymore for reasons known by the Sales department.
You're probably completely right. The optimist in me would have thought that it should be possible to tie the old and the new together in such a way that didn't detract from the overall potential of the game as a financial prospect. And the purist in me says that if you're going to develop a sequel to a beloved pre-existing creation it would seem...honourable, or at the very least, appropriate to do so. The lack of that makes me view the entire enterprise very cynically.
