My faith does not tell me I am forfeiting my sole by making someone a wedding cake. They took their faith to an extreme in my view. Either way, they can feel proud that despite such a personal cost they stayed true to their faith.
It is up to you. I wouldn’t call you stupid if you did or didn’t. It is between you and the Lord. But don’t call some stupid for standing by what they believe is serving the Lord.
Many believe that it shows a support of gay marriage, something unholy. Same for being a martyr. One would say these martyrs are taking a great personal loss for refusing to denounce their faith. Then again in this case, to die is to gain.