The problem of omelas

So last semester i took a philosophy class and a certain story impacted me more than the other. It was called The Ones Who Walk Away From Omelas" the premise is that omelas is your version of utopia. Anyway you could imagine it but in order for everyone in Omelas to have utopia a single child must be taken and locked away barely fed and deprived of human contact, Everyone knows of this child and its suffering. The teacher then asked you have 3 options, 1. Leave omelas 2. Free the child 3.Stay in omelas and do nothing. almost all of my co students chose leave or free the child. This idea seemed so obsured to me, the problem i saw with freeing the child is who gives them the right to destroy everyone elses utopia for the happiness of one child? how is that the right thing to do? make lets say 50,000 people lived in omelas and make them all suffer for this one child, doesnt seem right to me. maybe its because its a child and people feel its innocent? i dont know. 2nd even more obsured is leaving omelas its almost hypocritical being that we are americans that would mean you should give up almost all of your niceties in our world because people suffer to make them. No one wants to do that now but oh in a hypothetical situation thats what you should do? Hypocritical at best. and lastly the only choice that would be acceptable to me is staying in omelas, 1 person suffering for the rest of the people? sounds fantastic to me considering its almost 400:1 odds that 400 people suffer for one person.
 Next would be the problem of which child is picked? i think that it should be chosen by IQ of the child. the children with the lower IQ may not even have the capability to understand what is happening to them.