Even lower ratings?

Ok, according to tvbythenumbers.com, Prison Break ratings are at an all time low. Remember the last episode this past December before the hiatus? well that episode only pulled in about 4.8 viewers.
Prison Break's first episode for this spring only pulled in 3.39 million viewers. At one point, this show use to bring in ABOUT 12 million viewers every week and now it's gone down to 3.39? WOW!!! I don't think this "Dr. Sarah" having a baby is helping out too much either. I don't know, that just doesnt seem prison break-like to me. I am amazed (but not surprised) at how much the numbers have dropped. It went from being nominated for a golden globe award to being canceled and only having 3 million viewers... OUCH!!
Somewhere along the line, the writers screwed up. Don't get me wrong, they are very talented and have kept the show running for 4 years but the ratings kept declining. I think they tested our patience for too long with the story line and the viewers just lost patience with where the story was leading to. Now we brought back the dead, added a baby to the picture and broke in and out of prisons as we pleased... I mean... really! No wonder the show got canceled. I am not trashing the show at all so please don't take it the wrong way, I am just pointing out what might have led to such low ratings and cancellation. what's your take on it?