There's no denying that there is a high that comes from the street. It's a natural high, unlike what the pee-sniffing authorities would like you to believe. But there is also a tendency to romanticize street protests and to give the illusion that people spontaneously mobilize in a response to a stimulus. While the garbage pile up in the city is both visually and olfactory stimulating, street protests are organized events with multiple mobilizing groups. As the Beirut protests continue, the make up and size of the groups behind the mobilization are becoming clearer.
The leftist groups on the ground make up a good chunk of the mobilization and they are probably the majority if you count in the entire spectrum of left from Trotskyites to the Saudi-loyal "Left." Many of the leftist "coordinators" (apparently leader has a become a taboo word) claim to be aware that many of the other main groups on the ground and the ones being pushed to "coordinate above the rest" by establishment mass media are not going to deliver the change that is sought by them. But their argument is that word is now to the street and you have to be on the street to steer the mobilization your way. Incorruptible figures like Hanna Ghareeb and Charbel Nahas are invoked as insurance against the movement being taken in the "wrong" direction of globalized neoliberalism–or "depoliticization"–that promotes self-interest and individualism. It's not an Ego problem with some of the organizers; it's a political one.
That's not to mention the possibility of whole movement being co-opted by the ruling feudal oligarchy, which remains the most likely outcome. Yes they are corrupt, but they have offered the people something to gain their loyalties. They are people and not sheep as many in the protests keep referring to them, and the fact that the feudal and sectarian party is more appealing to them than the alternatives is a more of a condemnation of their foes than it is of them.
The continued failure to erode the sectarian divisions by leftist secular forces is because their activity over the past couple of decades has been largely limited to attempts at seizing opportunities created by circumstances. The abysmal performance of the ruling parties–like in today's garbage crisis–is an example of such an opportunity. Rarely, if ever, is this opportunity of their own making though, and there is always a sense of now-or-never-opportunism. The famous German saying "Einmal ist Keinmal" basically means that if something happens only once then it might as well not happen at all. Jumping on an opportunity created by your foes might lead to accidental gains, but only when you're making these opportunities you are in control and you can celebrate accumulated gains. Revolution is not a shout, it's a way of life.