I am not saying that Nepal government handled the situation brilliantly, but a bunch of 20 year olds don't just burn the parliament without some direction.
The way I see it is that a number of power groups (both internal and external) had been stoking the tension in Nepal for quite some time. The corruption and bad governance of the political class ensured that there was distrust for the elites in the public. In the present case, don't think Nepal banned the social media but asked those companies to adhere to local laws which they refused to do. So, sensing an opening, some of the power groups, would have provided the framework for large scale protests. But don't think anybody anticipated the situation to worsen so quickly. Now, am hearing reports that Army is trying to control the situation but there is still fear in Kathmandu, specially among elites.
It would be interesting to see which way does Nepal go from here. They were absolute monarchy till 50s with varying degrees of reform resulting in constitutional monarchy in 1990. And at this time, the King was very popular. But, this changed first with the Maoist led civil war and later with the royal massacre. Now, the king has been deposed, Maoists have joined politics and have been the dominant political force. So, where does Nepal go? Back to King Gyanendra, who is not as popular as previous kings but still has loyalty or Maoists, who have failed to provide any stability? Or will it be the elites of Koirala or Rana clan who will emerge as dark horses?