>>90606817He was a democratic socialist.
You're confusing that with being a social democrat.
He supported overthrowing business owners by force in a revolution, seizing private property, and organizing it so that everyone democratically controlled everything. Communism is further left than that, but that's still way, way further left than the left-leaning liberals that get called SJW's and leftists.
And saying he was against communism is probably a stretch. It wasn't the exact solution he favoured to capitalism, but it's unlikely he felt strongly against it as an end-point.
The reason he hated the USSR so much was because he saw it as a betrayal of socialism, not because he thought you shouldn't enact socialism. Also, the USSR was run by communists, but they never said that the country itself was communist. The big goal was to achieve socialism, which in marxist theory you need to have before you can even think about communism happening.