It's the spot where Julius Caesar's body was allegedly cremated after his assassination. People still venerate it by walking by and leaving flowers and coins and what not in his memory since he's arguably the most famous Roman in history. It may not be respect or worship, but serves as a memorial to a leader of ancient Rome.

Source: Just went over this same photo/last days of the republic in my history of Rome course.

Edit: /u/Caesar95 seems to be right as well on this. Just consulted a Roman anthropology book I had and found that among the different reasons for laying flowers, one is from "neofascists who continue to evoke Mussolini's exaggerated classicism and the ideals of romanita...an act of homage that apparently speaks more to the current political dynamics than to the historical personage of Caesar himself."

Source for edit: Shankland, David. Archaeology and Anthropology: Past, Present and Future. p. 52. London: Berg, 2012. Print.