While I very much dislike some of the changes (Women can be the dragon? The dragon might be split into multiple souls? That takes away the main threat of the dragon being a man, that he would be driven mad by the tainted power), I don't think they are to blame for the lack of depth. Maybe they are just trying to fit too much into too short a time frame, but the characters are so poorly developed that it's hard to empathize with any of them. I think it probably would have been better for chunks of the story to be cut out and worked around if they were going to go this far into the story in just a single season. Thom Merrilin, Padan Fain, those characters could have been taken out. It would be unfortunate not to have them, but you can't fit everything from a 14 book series into what is supposedly planned as an 8 season show, and they are characters that I think could be excluded without ruining the basic plot. As it stands, almost every character is little more than a shell of a person, so getting rid of some to flesh out the others would likely have improved things.
I agree, going slower and developing the characters, settings, and plot more deeply would have been better.