Government (and their partisan supporters such as some journalists, representatives) support their decision with the same old "think about children" argument.
For example this man in the video is the Minister of Transport, Maritime and Communication. He is the reponsible minister for internet in Turkey. Today some journalists asked him his opinions about Twitter ban and he responded "i will answer your question with another question. tell me what would you feel if someone opens a news twitter account with your wife's full name and shared photoshopped pics?".
(http://www.cnnturk.com/video/turkiye/ulastirma-bakani-elvani...)
Well, for your question: A lot of people saw that the ship is sinking and leaved it. The only people still supports erdogan are some business men who has some contracts with government, erdogan's inner circle and their base supporters who are mostly not well educated and don't have internet connection.
So, at least 40% of our country is against his censorship.