How is Piggy presented as a sympathetic character in Golding's 'Lord of the Flies'

Piggy has no parents. When he and Ralph first meet, Ralph shows a hero-worship of his father, to which PIggy can only respond, 'my dad's dead... and my mum' Golding immediately elicits sympathy from his reader, because Piggy has lost has lost the most important thing in his life. The contrast between Ralph and Piggy at this point heightens sympathy, because where Ralph's father is a high ranking Naval commander, who taught him valuable skills, like learning to swim, Piggy has no nurturing figures in his life. He doesn't have the strong male role model Ralph does, or the warmth of a mother. The lack of assurance that they are waiting for him back home makes him seem much more alone.
Jack's consistent rejection of Piggy throughout the novel is another reason to feel sympathy for Piggy. When Jack is first introduced, PIggy becomes quiet and reserved, perhaps recognizing him already as one of the bullies from back at home. A particularly heart-wrenching moment is when Jack says, 'We don't want you,' because it is evident that Piggy was hoping that life on this island would be different for him, 'as long as they don't call me what they did at school' The other boy's refusal to refer to him by his real name dehumanizes him throughout the novel. The direct address of Jack's 'We don't want you' is particularly cruel because it isolates Piggy as the only one without worth to the group.