Even if that's true, you're also giving your money to an organization that has these rules (and I do understand your position since I had the same decision to make a year ago).
Yup.
Unless you are planning to assume some high office within the BSA, just sending your non-homophobic child to meetings isn't going to change the organization from within.
I would never have brought this up with my son. But he came home yesterday wanting to do it; a lot of his friends are doing it. I can't very well tell him "I'm sorry honey, but these people are homophobic".
But you could certainly say, "I'm sorry, honey, but the organization practices discrimination against certain groups of people. We don't believe in discrimination in this house, so you'll have to play soccer instead."
That's exactly what we did with one of our kids when a similar situation arose, and she understood perfectly.