"If you own a business, you hire people who you think will help you make the most money, period. And at Marylou’s, the business model appears to be that, if given the choice of buying coffee from a chubby, grumpy middle-aged guy vs. a cute, bubbly 20-something girl, more people will choose the latter."
That being said, unattractiveness is not a protected class. If Marylou's only discriminates against people based on looks, that might not violate the law. But as attorney David Belfort told the Herald, "If you're serving coffee, I would think men could serve coffee adequately."