The catch is that the people who regularly ask questions are seldom the ones who ask the intelligent questions. The ones who pipe up if something relevant was really unclear and actually would be helpful to the class are a rarity. And they never get shunned like the OP, who is pretty clearly in the former group, based on the attitudes of his classmates as described in his post.
This is very true!!! This has happened many times in undergrad as well. Generally this is true of the people who ask multiple questions. The one's who have relevant questions are the ones who generally ask only one or two questions when they truly are confused or if a professor accidentally said the wrong thing, but the ones who ask constant questions like 10-20 in a row are usually wasting time and not often asking things that they can't do research on their own time to find the answers to.