Why is having multiple college majors seen as a bad thing when applying to graduate school? I have been told that triple (or more) majoring and/or taking numerous minors is seen as a bad quality when applying to graduate school. Can anybody explain we why they do not want academically oriented students that like to learn stuff?
It seems to be a common fallacy among undergraduate students that completing more majors and/or minors means that you have learned more in college.  I think this comes from the mistaken belief that completing the coursework required for a major in a subject means that you have mastered the subject.

In actuality, the coursework required for a major in a subject should be viewed as the minimum amount of coursework necessary to be able to claim any expertise in the subject.  If your goal is to study a subject at the graduate level, you typically want to take many additional undergraduate courses in the field beyond those required for a degree before you can reasonably begin graduate work.  Graduate schools look for this sort of deep experience in potential applicants, and tend to frown on those who have completed only the minimum requirements for a major.

So graduate schools don't see extra majors and minors as bad, exactly.  But if you spend time completing lots of extra majors and minors you probably won't have enough time to develop the expertise in your primary subject that you need for graduate school.  Instead of taking on a third major, you should plan to take roughly six extra courses in your primary field.  This might seem like it doesn't accomplish anything since it doesn't help you satisfy any official requirement, but it's exactly the sort of coursework that graduate schools are looking for.