We're not talking about hindsight. The people who got excited in the 30s, then backed away, are easy to forgive.
We're talking about people supporting soviet communism literally for decades after the evidence for the brutality required to sustain it was incontrovertible.
It's about the hindsight from your and my perspective, today.
Think about it: in another few decades people may (or may not) look back and wonder how intellectuals could support the system we have today despite of all the bad things happening.
We're talking about people supporting soviet communism literally for decades after the evidence for the brutality required to sustain it was incontrovertible.