We can assume that Proctor is not wholly impressed with Salem or his fellow inhabitants for a number of reasons. First, we learn right away of his keen dislike for Reverend Parris and Mr. Putnam, two of the town's most important leaders. Moreover, when Abigail gets him alone, hoping to rekindle their affair, she tells him,
I look for John Proctor that took me from my sleep and put knowledge in my heart! I never knew what pretense Salem was, I never knew the lying lessons I was taught by all these Christian women and their covenanted men!
The fact that Abigail credits Proctor with opening her eyes to whatever hypocrisy exists in the people of Salem confirms Miller's introduction of him; before Proctor arrives, Miller writes that "he had a sharp and biting way with hypocrites." In his presence, Miller continues, stupid people feel their stupidity right away, a fact that often makes Proctor unpopular. Therefore, it seems likely that Proctor believes many of his fellow Salemites to be duplicitous and perhaps even morally corrupt. At best, to him, they are idiots.
This is further supported by Proctor's words to Mr. Hale. Hale arrives at Parris's house and Proctor takes his leave, saying, "I've heard you to be a sensible man, Mr. Hale. I hope you'll leave some of it in Salem." Thus, we can ascertain that he believes his peers to be insensible. (His estimation of their stupidity is, essentially, proven by the fact that the trials are allowed to proceed as they do and continue for so long.)