I don't have a problem with telling attorneys that if you take a gay person on as a client, you have to give them the same level of professionaly commitment as you would any other client.
Would it be different if they put pedophile there or people with blonde hair?
Well, if you agree to represent someone charged with child molestation, you do owe them a duty of care when it comes to your work. Lawyers are supposed to be dispassionate in their work and represent their clients without predjudice.
Then, why not put in in the oath? If it's good enough for gays, it's good enough for them too then. But, it's not there, and there are plenty of "molesters".