It is entirely realistic and has happened several times in modern history, at least a few in the last decade
Two examples of not "single leader" protests happened in 2013, in Brazil and Turkey
https://en.m.wikipedia.org/wiki/2013_protests_in_Brazil
https://en.m.wikipedia.org/wiki/Gezi_Park_protests
P.S.: I don't have an opinion regarding whether Russian people are "responsible" for staying in Russia and "fixing" their government, but I upvoted everyone answering to this part of the thread/topic in a civil manner. Not many other places I could witness a discussion like this that does not degrade into insults