Earlier quoted context omitted.
Maybe he would, but all the experiments so far have failed for pretty much the same reasons and at enormous human cost. Meanwhile capitalism in whatever form it's tried has proven itself to be an incredible engine of poverty reduction and human/social progress. There's always been tension between capitalism and democracy and we may be at a point where some of the cracks are showing.
It's worth keeping in mind that we do live in the propaganda bubble of the Soviet Union's arch nemesis. For their KGB, we had our J. Edgar Hoover. For their political purges, we had our House Committee on Unamerican Activities. For their later economic struggles, we had our great depression.
That people, included in the UK elected representatives, make a case for the Soviet Union and Communist China having done more good than bad is a a terrible failure of history.