The problem of Net Pracharat is their transparency as mentioned coconuts news about the issues that the purpose of the project is unknown. As the Thailand’s government have the Cybersecurity Act which can monitor the internet traffic without court review, creating a massive free WiFi network could risk the citizen privacy and data unless good Law enforcement does not made in time .There have been such issues in the United State as well like Massive Surveillance Projects which does not need any legal warrant. For details, you should read “Permanent Record” by Edward Snowden.
The sustainability of the project is also import. To maintain a good internet speed, before people get frustrated after they know how to use the Internet. Those will look for the good services providers whether it is free or not because they already know the benefit of Internet.