Would it be a bad idea to hold my daughter back in kindergarten?

My daughter is five now and started school when she was only four. She does well but has already developed a bad attitude about going. I've visited her cl several times and come to find that one of the teachers aids is really unpleasant. During one visit for lunch, she repeatedly made a little boy look like a fool in front of the whole cl, along with rolling her eyes and sighing loudly with disapproval. It makes me wonder if she act like that to my daughter because the other day after school my daughter commented to me "It was the best day cause Ms.----- wasn't there." I want my daughter to have better feelings about going to school and maybe if she didn't have such a negative learning environment she could enjoy it more. I do plan on switching schools next year as well.