why do Marullus and flavius feel the need to take down the decorations

This question has been asked in various ways on this site. Basically The tribunes Marullus and Flavius are angry with the plebeians because they are cheering for Caesar. They do not think that Caeser represents Rome and wish to put the brakes on his building power. They find the plebians fickle and weak noting that they used to celebrate Pmpey, a Pompey that Caeser killed. Flavius and Marullus take down banners and decorations and to drive the crowds of supporters away.