Sami Ibrahim has a personal agenda against Nawaz Sharif. One can start watching all his shows/programs and can easily see the biased in his reporting and presenting of situations.
As far as the protest goes, one has to get a formal permission from the city for any protest at any location, let alone in the capital. And the permission comes with certain restrictions and/or boundaries. I am sure if the gentleman above claimed that he counted 0.2 million bikes' wheels ([hilar]), despite how much unrealistic it may appear, there must be that many people but if the protest was not authorized to begin with and the protesters started moving towards important institutions, it had to be stopped. Since the government did want to repeat another 'model town' episode, they have no option but to try other peaceful means to disperse the crowd, like tear gas shelling, stopping supply of food and water, etc, etc.
If any party opposes any proposed change to constitution, they can do this via peaceful protests and show their intention. Or, have a majority in the assembly to block such change. This is how 'normal' people tend to do business in 'normal' countries.
My above explanation is for people who accepts logic, not for brainwashed folks or politically biased folks who believe in the saying 'an enemy of my enemy is my friend' to try to get advantage of the situation. For those folks, all I have to say is, just wait as, 'what goes around, comes around'.