1. The fact that a black person is discriminated against doesn't usually mean that person wishes to become white. The same applies to me.
One can hate the discrimination without hating the condition just because we get cross when we are discriminated against does not mean that we don't like who or what we are...
I complain about discrimination which I have experienced all my life. That does not mean I am complaining about being blind. There is an automatic assumption that disability is utterly bad news... I don't think that is so. There are some bad things about it and some amazing things about it and most of the bad things would be better if the people around us had a better attitude.
2. You don't have to be an atheist to argue against religion and religiosity. If an intangible idea which can be described but not seen or touched is nonetheless definitely present in people, then, by that definition, it exists.
Beliefs such as xenophobia, worship of money, lucky charms – they are all real. We don't deny they are real, we just don't approve of the people who espouse these notions, nor of the notions themselves.
Belief in God or Gods is real. Therefore the God or Gods themselves are as real as racism.
In the same way that we can take issue with collective xenophobia, corporate greed or anger with thoughts of violence, so we can take issue with God as incarnated by religions and say 'I accept that God or Gods exist – definitely – but I dislike and disapprove of religions and religiosity as aspects of human thinking and belief'. Righteousness, superiority, intolerance, fundamental denial of all geological and zoological history – I think these are all very bad things.