Why Does ABC Cancel Good Shows?

ABC is probably the television channel I watch the most; my favorite soap opera General Hospital is on ABC. However, sometimes I question ABC and what they believe qualifies a show as a good program.
I understand it is a recession and reality television is easier to produce, but it makes no sense to cancel good and highly entertaining shows. The weird thing is that they create new shows to replace the ones they cancel and end up canceling those too.
First there was Pushing Daisies. I loved that show. Not only was the premise of the show different and interesting, but it was also intriguing visually. The acting was incredible and the stories were original. After only one and a half seasons, ABC decided to cancel saying that it was too expensive to produce. I guess all of the Emmy nominations weren't enough to show ABC that Pushing Daisies was a substantive show.
Next, they canceled Life On Mars. Now, in the beginning I wasn't very interested in the show but after watching it with my mom, I found it to be very entertaining. Again, it had a very different premise and I love that. Then they canceled Samantha Who. I loved that show and thought the characters were hilarious. I looked forward to watching that show every week. And way to kick a girl while she's down ABC. You cancel a woman's show while she is battling Breast Cancer.
Now they have canceled Ugly Betty after four years. Ugly Betty is an amazing show and it is so inspiring. It's a show that everyday people can relate to. I can relate to Betty and her struggle to get where she wants to be in her life. I can relate to her as a writer and wanting to succeed. The issues of Ugly Betty aren't high brow and most people can find some commonalities in the show with their regular lives.
I understand needing to cut costs but don't sacrifice quality television for the sake of cost; it only demeans your television station as a whole. I think ABC needs to take a look at their complete program list and really decide what shows need to stay or go. Personally, I would much rather watch a show like Ugly Betty or Pushing Daisies rather than the Bachelor.