it was a difficult show, for sure. I'm not sure how much further Rachel would have gone - she has difficult with turning, spotting and balance, which have not improved since she's been in the show, but that said, there are some who are worse dancers than Rachel and if we're being fair, they should have been voted off first.
The trouble is, the voting public aren't voting for the dancing. They want to be entertained and that's how they vote. The producers would have to change the nature of the show, and the voting system, to get back to the dancing. I do wonder how much the voters know about dancing, or care ?