community?

I have become increasingly suspicious of the word "community" - as in LGBT community, Muslim community, Pagan community, being used to describe a group of people with a shared characteristic. It includes the assumption that the community does or even must speak with one voice, and that there are leaders of the community who will be the transmitters of that voice. It includes the assumption that identity is discrete - you are either Pagan or Christian but can't be both, for example. It is also divisive, setting one community against another. Similar ideas were expressed on Radio 4's Thought for the Day [Listen] [Read] this morning, which I found interesting, and thought "I'm glad it's not just me that's noticed this". Surely we are all part of the community of sentient beings, ultimately?