Without dealing with Zogt’s answer, I am not sure how strongly disagreeing means one has to use derogatory language.
There is a very big difference.
And in most cases, I would certainly give a bonifide, universally acknowledged gadol the benefit that he knows something I don’t.
For instance, I personally do not follow all the shittos of the Divrei Yoel, but I would not use degrading language to talk about him ChV.
Like a certain posters snide remark.
And Sam, although I do not agree with much you say, I find you typically to be knowledgeable and reasoned, I am therefore surprised with your assumption that strongly disagreeing means ridiculing.