You're under the impression that Ron was somehow forced into this. Harry had attempted to ward them off coming on this journey several times, but they were adamant about going; he told them all he could—they were still adamant about going. They knew the risks, they knew what it was going to be like, Ron was unprepared and arrogant. Once again, his choice. He had every opportunity to leave, he had every opportunity to not go. He had no obligations to Harry, and Harry would have likely felt less betrayed if he just didn't go in the first place. He's 18 years old. Teenage hormones have nothing to do with this, nor do I think Rowling ever presented that in the story as an obvious threat. You keep repeating about how Ron is only human, but that just shows me that he's one dimensional. Some people theorize that he is exactly like them, and that is why individuals dislike his character. I think that's a pretty big generalization. People dont' like Ron because he doesn't progress. He's been doing the same thing, over and over again, it's like watching a broken record continually regressing. People dislike him because he is uninteresting.