There are plenty of places you can minister to Muslims, I do it often. There is nothing wrong with having a place for fellowship alone. I mean, we dont open the doors of our churches to all false prophets to come and debate with us, do we? There are plenty of places to deal with such things, at the same time it is also good to have a place where Christians can come together just for the sake of the Bible to share with and help each other.
Of course there is nothing wrong with having a place for fellowship alone, but there is nothing wrong with having one place on the forum for interreligious or comparative religious discussion or debates or a witnessing section to reach unbelievers. Christianity is not just about fellowship.
If an unbeliever, a cult member or a believer in another faith is not civil or respectful, they could be cut off. We could have most sections for fellowship alone on the forum and just one for witnessing. Besides, you would be naïve, IMO, if you didn't think there aren't false teachings on this forum now (False prophets). That is more insidious than a Muslim or Mormon coming on asking questions or trying to proof they have truth.
Everyone is entitled to their opinion. I respect yours, but I just don't agree with you about that. Our church is open for everyone; some churches would turn Jesus or angels away unawares.
Where do you find plenty of places to witness to Muslims?