If, for example, three vendors provide the same service and two of them offer no opinion at all whereas one vendor espouses an opinion I find distasteful, it is not only OK, but imperative that I vote with my wallet. It simply isn't good business to offer personal opinions on divisive topics to ones customers, the personal opinions of the proprietor become the defacto opinion of the whole business. I fully support ones right to have any opinion whatsoever, that being said, if I were to support with my money, those who support the restriction of my constitutional rights, then I would be a traitor to my own beliefs.