I never had a problem with the death of the communists. It was a civil war in the making and targeted killings is quite appropriate. Were Mussolini had done so rather than allowing communists to write books.
The problem with Mussolini is he was a socialist and in many ways identified with Gramsci. The fascists were lesser brutes than their german cousins. It did have a positive side. A far greater number of jews survived in Italian occupied Europe than otherwise would have happened. The fact he allowed people like Gramsci to write in prison is in hindsight a historical mistake we will pay for long into the future. If only history would work out as it should into a neat little package instead of the supreme mess that it is.