If we generalize this problem, it basically distills down to: If you are a web designer and a <protected class> commissions you to make a website glorifying <something you personally find to be immoral>, are you allowed to refuse the job on grounds that you don't want to use your skills to promote something you personally find immoral (though you would be happy to make them other content you don't object to)? Or should you be forced by law to make the website in order to not discriminate against <protected class>?