not think much of

not think much of

Have little regard for, have a low opinion of, as in Bill doesn't think much of the carpentry work in that house. The phrase not much has been used in this sense since the mid-1800s.
See also: much, not, of, think
References in classic literature ?
Ay, James, lad, so it is; but I should not think much of you if you could leave your home for the first time and not feel it.
Comer does not think much of some of the approaches that are popular with many of the readers of this journal.
However, my mother did not think much of the Western lifestyle in which she found our family.
In a word, he does not think much of you for this opening, and it sounds like he does not think much at all.