I really like sci-fi and comics and all that crap, and I haven't seen Dollhouse, but I did watch the first 3 or so episodes of Fringe and I think it was pretty bad. Like a bad mix of X-Files and Lost. And it was getting terrible ratings, so why should they be faithful to it? I gave Sarah Connor an entire season and every second of it I absolutely hated. It is just a plain terrible show. Terrible dialog. Terrible writing in general. Terrible pretty much everything except hot chicks kicking ass. Which is nice and all, but eventually the stupid dialog and asinine plot lines get to you. And I love T2, and I think the premise of the series is excellent, but it just isn't well executed.
They gave Sarah Connor plenty of time to make it. Maybe they didn't give Fringe a good enough chance, not sure, but I certainly am not going to complain. If either of those shows were 1/4 as good as Alias Season 1 I would have stayed for the duration even as it declined into terribleness.