Stereotyping all muslims (or any other group of people) is being racist/ethnist/etc, whether you act on it or not.
This is an important point, but it is not as simple as it seems.
Various groups of people do share beliefs, cultures, traditions etc. Must one ignore these when considering how to interact with a person who belongs to one such group? Is it, in some cases, even safe to ignore these shared attributes?
As an example, would it be a good idea to invite a muslim to a pork dinner?
I think that membership in a group increases the likelihood that they will possess the characteristic traditions etc of that group, even if it does not guarantee it.
What I see is that identifiable groups complain that their identity is not being taken into account at some times, and at other times that it is. The difference being which complaint is to their benefit.
One is either a part of the wider society, or not. The problem for well-meaning people is to tell which applies is in particular cases.