Actually, a significant number of people at HBS had liberal arts degrees. And they did just fine, even with the maths. In fact, in many ways, they brought creative, innovative approaches to case studies. And I dare say they are not struggling finding employment in the work place.
A liberal arts degree is a great foundation for not only success in graduate work but in life.
Anyone that gets into the Harvard Business School is going to "do just fine" ... no other details are necessary.
I agree that liberal arts is a fantastic degree ... my HS senior daughter is planning on studying liberal arts this fall. If you do study liberal arts, hopefully it is with a plan in mind, like applying for law school or graduate (business/medical) school. This is a fine course of action. If, on the other hand, you plan on studying literature for 3 1/2 years and then walk into the placement office to see what's available, you're in trouble.