Logical (the Byzantine Senate was controlled by the aristocrats, the only social class which could maybe produce some republican opposition), but regrettable. Beside this particular timelime: I wonder if the Byzantine were aware of the little, not very important fact that the empire, the whole base of the Byzantine state was built under and by a republic, which was the state of their ancestors? Nevertheless, I admit that the medieval republics to which a Byzantine could refer, were little and annoying ennemies of the empire's power and more a plague than an actual lighthouse of temperate, popular government.