You do realize this kind of thing actually happens, right? The right wing of american politics is an avid user of and believer in boycotts.
Personally, I have no issue with this. No company is entitled to a person's money, and if they make their public face about politics they accept the consequences, both good and bad, of doing that. And it really is worth noting that there are often positive consequences of doing it as well. Even for causes I disagree with. Chick-Fil-A probably came out a bit ahead, if anything, since their presence was stronger in markets that supported them.
Likewise, Disney openly supporting gay rights through Gay Days at Disneyland and making sure their insurance supports gay employees' families have had both positive and negative impacts.
This faux-freedom argument, where people aren't entitled to decide how their own money is spent but the richest and most powerful are entitled to do whatever they want with theirs without any fear of consequence is just a ridiculous double standard.