I really enjoy Lisas dances. I never had low expectations for her, I made no assumptions. I certainly never assumed she wouldn't be able to dance because of her size. I've seen several highly skilled dancers who happen to be 'large'.
I was pleased she broke some expectations. But as some mentioned, people were so impressed, they expect that kind of shock every week. Whilst she's been good, and one of the better dances there, she certainly isn't the best. She has improved, but not in leaps and bounds. For some that shock hasn't been sustained, which no one would be able to do. It's all to do with expectation.
Lisa is a great dancer with very respectable overall technicality and even better 'performance'. I want to see her refine her moves some more. She showed last week she is starting to focus more on the technicality and I really hope she continues that this week. But no matter how much she refines her moves, some people will always find spurious reasons to bitch about her, which is fine, they can do as they please. But most of the reasons I've seen so far have very little grounding other than a kneejerk dislike of her. At best, some of the reason have been greatly exaggerated.
But she is one of, if not, my favourite contestant in the competition. She's a respectably good technical dancer and has clean lines, great rythym, light footwork and energy. Most importantly, what she has that no one else does is warmth and charisma when she dances. She shines on that floor and sells it.
As for the negativity. Just take the bits you like and leave the rest.