What is it that Gulliver dislikes about the Brobdingnagians?

Much of what Gulliver dislikes about the Brobdingnagians is physical. These people are giants, but they are peaceful giants. They occassionally fight in wars, but they keep an army as a source of peace rather than aggression. The King is powerful, but he rejects things like gunpowder. Physically though, it's a different story. Gulliver sees the people as ugly, their normal, human traits disgust him.

What we're talking about here is the magnification Gulliver experiences in relation to the human body. The Brobdingnagians are giants, but they look no different to him than he must have appeared to the people of Lilliput. Moles, pores, hairs, breastfeeding, and so on, become disgusting to him because every flaw is amplified by its size. This experience so appalls him that he has no sexual interest in his wife after returning home. In other words, the things he disliked changed his perspective and life.