I would highly recommend majoring in mathematics to any student with an interest in mathematics. I think majoring in mathematics is fun and that the career opportunities are unlimited. These are the best two reasons I can think of to help a student decide whether or not to major in mathematics. For students who enjoy math in general but can't decide what to major in, I would suggest that math is an excellent, versatile, very marketable undergraduate degree. You don't have to be brilliant to do well in undergrad math courses.
All businesses love math majors because math trains for a good form of problem solving.
Mathematics is probably the best foundation anyone who plans to pursue academics can have. The training in mathematics is indispensible for me, but not for reasons that are readily apparent. Mathematics trains one's mind in clear, logical reasoning. It challenges one to deal with abstractions and to see how these abstractions have an inherent r elationship to real phenomena. Mathematics teaches one to think logically.