The F/Os who make these sort of comments tend to believe they should be doing the LHS job, and the criticism usually conveys their own frustration rather than any "high and mighty" attitude that they can do the job better than the current guy in the LHS. (Although I concede that some of them do!) This gains them a bad name among the captains and people begin to expect that they will have to endure various putdowns and veiled criticism whilst flying with them, which puts the whole day on edge.
Unsurprisingly, when they do become Captains, they are "grabby" about flying sectors, overly critical with their own F/Os, weak on CRM, and generally set the whole day on edge as you feel you will be flying with a martinet and more likely to make mistakes.
From the CRM p.o.v. these people should be taken aside early on and given a few home truths to prevent them dragging a legacy of bad crew co-operation for the balance of their flying career. In such cases the individual makes all the difference!