Well either these people are wrong....
https://atheist-community.org/
Or you are.
They are.
If you take the Merriam-Webster Definition of Community you get
1: a unified body of individuals: such as
a: the people with common interests living in a particular area broadly : the area itself the problems of a large community
b: a group of people with a common characteristic or interest living together within a larger society a community of retired persons a monastic community
c: a body of persons of common and especially professional interests scattered through a larger society, the academic community, the scientific community
d: a body of persons or nations having a common history or common social, economic, and political interests, the international community
e: a group linked by a common policy
f: an interacting population of various kinds of individuals (such as species) in a common location
g: state, commonwealth
a: fails by atheists only sharing one common interest
b: fails by the living together aspect
c: fails due to the common interests
d: fails due to not having a common history
e: fails as there are no common policies
f: fail due to location
g: not a state