[_delirium]

In some situations I think it's just because other people don't have to listen to them, so people who are overloaded with input ignore the easiest-to-ignore input. If there are five opinions, and two are non-confrontational and will probably not cause a fuss if you ignore them, the path of least resistance is to ignore those two and figure out how to sort out the remaining three. Not even necessarily a conscious decision in some cases.