I didn't think Alesha did that badly last year, but I think she has improved this year. She seems more comfortable and confident. Fair play to her, she has been given a rough time in the press. It wasn't that long ago everyone moaned about Arlene – I actually found her painful to watch sometimes.
Yes, I think it's awful there was blatant ageism in the decision to sack Arlene. Yes, there are people more qualified to do Alesha's job, but that's not what it's about. She's not judging a full on dancing competition, she is there as a former winner and somewhat talented semi-pro dancer herself (and when I say semi-pro, I mean, she's a pop star and she was paid and won a TV dancing competition).
And honestly, all the snipping about her grammar, ey ey ey. Language is never static and evolves constantly – the standard English language we speak now is a bastardisation of what went before and what was previously considered 'good grammar'. What we are taught is 'good grammar' nowadays, (or even language deemed highbrow), was, at one point, as colloquial as Alesha's use of language today.
I do wonder if there would be the same kind of backlash, if say, a former male contestant replaced Bruno, or any of the others.
She is unlikely to be going anywhere this series, so perhaps you need to find ways to live with it.