They may not want to hear the word of God preached, but those people most definitely need to be in that Church.
In the words of Jesus:
“It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners to repentance.”
If anyone needs to go to a Church and hear the word of God, it is those who are in the worst states of sin.
No, they don't. To use your (and Jesus's) analogy of the sick needing a doctor, those people rejected the treatment. There's no need to be in a hospital or a doctor's office if one rejects the treatment. Those people may as well go to some quack who will tell them what they want to hear because they are in denial about their condition.
And BTW, just because the remaining members did not make a show of walking out it does not mean they are not likewise sick and in need of a physician. The Bible is quite clear that all are sinners. The gay lobby and their fellow travelers simply refuse to see homosexuality as a sin.