Proletarians with minds and ideas of their own are people the middle class are afraid of. Even middle class leftists, who use social change movements to mobilise people to their own ends, who use empty slogans in order to attract frustrated workers.
The problem with this is that for proletarians to bring about change that will improve their lives, it has to be born from them. The leadership idea has to be overcome, as does the leadership itself existing in social change movements, who are mainly middle class people. The middle class in their various positions in society are antagonistic towards workers, and are integral to the control and pacification of workers through the various institutions they represent and control, even in areas of "social care". The relationships the middle class have with workers are bound up with rules of inequality, power and privilege, or rulers and ruled.
A workers movement for social change is not a genuine workers movement when the leadership are middle class. The power will not have gone away from the oppressors to the oppressed.
Karl Marx himself was middle class, and individuals within this class can help workers, and join them, but leadership, if it has to be used, must come from the workers and not the middle class, which does not occur with social change movements today.
To have exclusivity for one class is wrong people may suggest. But, in the main workers are exploited by a capitalist system, and middle class regulators- these watchmen, lackies of the system, have more power and postion in society, and this is of deteriment to workers, and relationships between them will carry negative qualities that couild ruin social change.