Well this is interesting. The channel has now gone off the air completely. However, Comcast still lists it in their guide. It just goes to nothing.
I've wondered the same thing about WGBX 44. I posted about it in another thread about a year ago. I can't understand the point of it anymore.
However, when I was a kid, I always thought it was GREAT having all those PBS stations. I had a total of 4 on cable. I had the ones listed above, as well as WENH 11 out of New Hampshire. I remember being able to see Sesame Street sometimes up to 8 times a day. But maybe that's just me.