Well, Brutus’ actions from another perspective may have been regarded as patriotic, since he was dead-against Caesar being a dictator for life and his de-facto god-king status. Now what if he had won at Philippi against Antony and Octavius (who became Augustus)? Would Rome have been restored as a republic instead of becoming the autocratic empire?
The reality was, Brutus stabbed Caesar and apparently was part a plan to do it. That was treason and the ultimate in personal back stabbing, "Et tu Brute!"