Let's be real: George Pollard Jr. was probably never meant to head a whaleship. He's more Captain Kangaroo Captain Jack Sparrow, which is just about the last thing you want from a guy in charge of a ship like the Essex.
Throughout the journey, Pollard lets his subordinates—especially Chase and Joy—push him around. The first time this happens is when the Essex nearly flips over just days after its departure. Pollard wants to return home, but he's convinced otherwise by his mates. Something similar happens again after the Essex sinks: Chase and Joy convince Pollard to take the longer (and much more dangerous) route to South America rather than head over to the nearby Society Islands. In both of these instances, "Pollard had known better, but instead of pulling rank [...] he embraced a more democratic style of command" (6.29).
As it turns out, that's the worst style of command to have in situations like these. Disasters—which seem to happen constantly on whaleships—require split-second decision-making skills, not to mention the confidence to follow through on those decisions. Unfortunately, Pollard is majorly deficient in both of these qualities.
Lest we blame his failures solely on Chase and Joy, we get to see Captain Pollard act identically on his next mission as captain. As his ship goes down—for the second time in the matter of a year—Pollard once again "lapsed into his former state of mesmerized despair [...] unwilling to leave the ship" (14.10). We don't care if you're talking Captain Kirk or Captain Hook—that kind of inaction isn't going to fly.
As it turns out, this will be his final mission. Pollard spends the rest of his days working as the night watchman in Nantucket: a cush job. Though he carries memories of the Essex disaster to his grave (notably fasting on its anniversary each year), he seems content with his new, simpler life. After everything this dude has been through, we'd say he's earned some R&R.