The Establishment do not want a proper left-wing government. A proper left-wing government would create a fairer country and take money away from the wealthy. They’d give working people a better deal. They would put a stop to privatisation putting money in the pockets of the wealthy. They’d promote public services.
What the Establishment want is to continue to keep wages low and profits high, to tax low so they keep more of their ill-gotten gains, to privatise so there is more opportunities for rich people to make a fortune.
When Corbyn very nearly got in they panicked. All the stops were pulled out. He was vilified as an unelectable extremist. They’d rather have bloody Johnson – a clown, a buffoon, a lying bastard, an idle, incompetent twat, but at least one of theirs.