Disconnect of “Left Intellectuals” from Working People

perhaps someone can explain me
- what is a "left" intellectual
- who forced the disconnection, how, when
- why do working people need left intellectuals to improve their life (I mean: the life of the working man,  not the life of the intellectual of course)
- is it possible that, in order to fulfill the life of left intellectuals, you are in desperate need of working class people

The video does not seem to match the description .
It's good but not what was advertised.