Maybe Arlene did overstep the mark when airing her views about JS in last series, but she only said what nearly everyone (well, a heck of a lot of people) was thinking and saying among themselves. Should she have spoken out to the media? That's another question. Unless there is some rule in their contracts that they shouldn 't speak out unless actually in their judges chair, then I have no great problem with it.
As for "Hating" Arlene.... Hate is a very strong emotion, and certainly not one I would feel against someone on the telly simply because I didn't always agree their views, or the way they delivered them.
I actually liked the panel, even though Bruno sends me mad with his daft antics, and seldom has anything constructive to say, and given the popularity of the show I would have said "If it ain't broke, don't mend it!"
However, as changes were on the table even before the last series was ended (and you can bet you life there will be more made next year) and a change of judge/judges was thought viable, then whichever judge they chose to replace SHOULD have been someone with dance knowledge and experience, the fact they have chosen someone for their looks as opposed to their knowledge, is where the beeb have blundered - big time!