If the best defense you have is that you have the right to be a jerk, then you should probably really reconsider your opinion.
First off, fighting discrimination is not about making sure no one's feelings get hurt. In the case of gay individuals, a lot of them are actively assaulted or murdered or commit suicide - by encouraging further discrimination against them you are actively encouraging violence against them. If someone kills themselves because they are not accepted in the world - then that's not hurting their feeling, that's causing them to die.
I can't believe how, in a country where people fought for the right to be able to enter any restaurant they wish, to not have to sit at the back of the bus but be allowed to sit in the front, there are people now that are arguing that NO we should be able to say "sorry, you're not allowed here because I don't like your kind." Are things really that backward just across our border?
OKAY, try to put yourself in their shoes. If you walked into a store, just to order some cake, and the owner said "sorry we don't serve you white trash here" how would you react? If you signed up for a university class, and paid, and then the faculty said "we're going to kick you out of this class because we don't approve of white people taking classes." If you walked into a market owned by a super hardcore religious person, and they said "sorry, you have a girlfriend, she's clearly a sinner by being so promiscuous and is going to burn in hell so we refuse to serve you" would you just go "okay you have your freedom, I'm just going to walk out now." If you extend this argument even further, Saudi Arabia is an absolute monarchy, therefore the entire country belongs to the king, yeah? So when the king goes "yeah, women, not driving, they don't deserve it" would you go "yeah, seems fair, it's his country." Why do we make such a fuss about women not having rights in Saudi Arabia then, it's their property.
It's not like gay individuals are asking cake makers to write slogans like "SCREW STRAIGHT PEOPLE" on their cakes, or asking them to take a stance. They're just paying money because they want a damn cake. It's not your business what their private life is like, all your concern is that you get your money in exchange for a cake.
But what can I say to 'MURICA Land of the Free*
*restrictions may apply. Freedom™ not applicable to gay, lesbian, bisexual, transgender individuals. Muslims, Latinos, immigrants, black people, brown people need not apply. In case of women, Freedom™ may be restricted, equal pay not ensured. If a country possesses oil, Freedom™ will be taken to them. To take full advantage of Freedom™ it is advised to be born white, straight, male, and Christian, and remain so for the duration of taking advantage of Freedom™