Unfortunately for him, Piggy is the character in Lord of the Flies by William Golding that everyone loves to hate. When Ralph first meets Piggy, he puts up with Piggy's chatter and questions, but as soon as he can, Ralph tries to get away from him. While the little ones answer Piggy's questions, they do not even consider voting for him as their leader--despite the fact that "what intelligence had been shown [on the island so far] was traceable to Piggy." Jack literally hates Piggy from the first moment Piggy opens his mouth to speak. From the beginning, Piggy is on the outside of the circle of boys.
This is probably due to the fact that Piggy is such an unappealing physical presence. He is distinctly overweight, wears a windbreaker (a rather "sissy" thing to wear in this crowd, apparently), has asthma, and wears thick glasses. These are schoolboys, remember, and there is nothing much crueler than a bunch of kids who find something to pick on in a person they may not even know. This is what happens to Piggy with Ralph and the littluns; however, with Jack things are different. Jack clearly sees Piggy as a threat to his (Jack's) leadership and wants to shut him up from the outset.
When the boys vote for thier leader, Piggy does not vote for either Jack or Ralph, seeming to understand that neither of them is a particularly good leader. Jack has already demonstrated that he is a poor leader by having to coerce his choir to vote for him. Ralph takes a cheap shot at Piggy by revealing his nickname, the one thing he asked Ralph not to do. In short, Piggy is the most intelligent boy on the island because he understands these things before anyone else does.
So, no one wants Piggy on their team, so to speak. At meetings he tries to follow the rules of the conch but is shut down and stifled at every turn. When the boys decide to make a small fire on the mountain, everyone races off, leaving the asthmatic Piggy to makes his way alone and at his own pace. The boys amass a huge pile of wood and then stand there, embarrassed because they have no way to light the fire. They look around but see nothing to use.
A little air was moving over the mountain. Piggy came with it, in shorts and shirt, laboring cautiously out of the forest with the evening sunlight gleaming from his glasses. He held the conch under his arm.
Almost immediately he is mauled and his glasses ripped off of his face so they can make a fire.
The great irony is that no one needs or wants Piggy's physical presence, his intellect, or his commitment to the rules (as demonstrated by his understanding of and care for the conch). Nevertheless, it is his glasses which hold the power of life and death on this island, for fire has the power to save and destroy. Piggy, the boy everyone loves to hate, has the absolute key to life and death on the island: not intelligence, not order and discipline, but fire.