They would gladly sell any gay flowers for a birthday or Mother's Day, Valentines, but they don't want to serve a gay wedding. Then that is not discrimination. They are just choosing not to provide a particular service like a gay wedding, just like a restaurant may choose not to serve pizza.
A totally fallacious argument. Fact is the florist does serve STRAIGHT weddings. Your "no pizza served at all" argument might work if the florist served no weddings at all.
Other facts: the gay couple had been buying from this florist for years. Also, Richland, Washington isn't exactly a large metropolis, and includes rural areas. (I lived in Washington 5 years) It's not clear if they had a better boycott alternative from which they wanted to buy.
But in any case, as an American who values equal treatment as guaranteed to me by the law, I'm not sure I would have let this florist get off so easily, either. Not as some in this post are suggesting we should do.
Sure, gay guys, just run away with your tails between your legs. Well, I'm glad this gay couple didn't do that, but fought back, standing up for all of us. For our rights and our principles of equality. Congratulations!