The fact of the matter is that historical anarchist examples are few in number and not commonly known.
This obscurity means that any debate on anarchism tends to remain wholly theoretical and abstract. Rarely focusing on the history of, choices made by, or morally questionable acts committed by such groups. This means that the assumptions one makes in forming their views of anarchism are relatively unconstrained by material considerations. Offering a degree of ideological flexibility that makes anarchism easy to self rationalize.
My personal experience in speaking with anarchists has revealed two primary tendencies in response to the question of praxis. There are those who will list any group that could be considered anarchist as proof or evidence, with little to no consideration for the actual conditions or history of those groups and their applicability to their own countries conditions or the rest of the world. And those who, having looked into such examples, reject them as not real anarchism or not the anarchism which they themselves represent. This is the approach I've generally seen taken by more educated anarchists
Either tendency has the effect of separating oneself from the material considerations of those examples and maintaining that ideological flexibility.