I've held to one or another version of this perspective from the very first year of this list. Too many posts at that time raised the fake question, "What is wrong with The Left,' ignoring a fundamental fact of capitalist history: the _normal_ state of affairs is working-class weakness (and hence the _absence_ not the 'weakness' of anything that could properly be labelled, 'The Left.'"
I have now reached the position that the only persons that are leftists (and hence in a position to criticize leftists from a shared perspective are those who are active members, at the local level, of some Left Organization -- that is, some local organization in which the members regard the ultimate aim of the group to be participation in some national mass movement, and organize their local activities from the perspective of such a hypothetical future.
Carrol