The magnitude is absolutely irrelevant. Hypocrisy is hypocrisy, and the core issue here is whether or not people have the right to boycott a product over the beliefs or actions of the people who are associated with the product.

If I believe that cars are causing global warming, I have the right to boycott the uses of cars and to publicize it. If I believe that eating meat is wrong, I have the right to boycott meat and to publicize it. If the CEO of a company supports a campaign that I believe infringes on human rights, I have the right to boycott that product and to publicize it. If the company of a product I use adds a person who was involved with what I believe was an unjust war that killed hundreds of thousands of people, the I have the right to boycott them and to publicize it.