Conferences at a Middle School

Conferences are always interesting to me.  The preparation by the staff and teachers.  The parents who make the time to show up in order to find out how their child is fairing early in the school year.  The one issue that tends to baffle me the most is how many parents show up for the students who are straight A students vs the students who may not be doing as well in their classes.  Does anyone have an opinion about why this trend seems to continue?