Why do Marullus and Flavius take decorations off Caesar's statues?

Marullus and Flavius are horrified by the citizens’ celebrations upon Caesar’s return to Rome after the defeat of Pompey. Pompey was a hero whom the citizens loved and his opposition to Caesar led to a civil war. Caesar prevailed, and the citizens, once loyal to Pompey, now “strew flowers in his [Caesar’s] way” to celebrate Pompey’s defeat. Marullus and Flavius are angry at how easily the citizens’ loyalty shifts and how quickly they forget who they support in favor of whoever is in power. As the tribunes of the people, Marullus and Flavius likely petitioned the Senate on behalf of the citizens in support of Pompey in the past; with Pompey now dead and Caesar ascendant, Marullus and Flavius find themselves worryingly on the losing side. Their fates are far from certain, and to add insult to possibly fatal injury, the citizens they represent have double-crossed them and expediently switched their allegiance to Caesar. Marullus and Flavius can’t stand the idea of Caesar being triumphantly welcomed and decide at the very least (though Marullus is a bit hesitant) to take the celebratory wreaths and garlands off the statues. Later on, Casca reports that both of them were “put to silence,” an enigmatic statement that suggests that they were right to fear for their lives under a Caesar regime.