You probably have not lived in China (or singapore) and are hence making the comment. What usually happens is some authorities float a project idea on the news. At this point the idea would be toyed with. Depending on feedback gathered via academic studies and social media responses, if the project is seen as controversial the projects scope will be adjusted to some common ground that works well enough for most of the identified stakeholders involved - this is what the civil servants are paid to do. In china this usually is an ongoing dialog between local and central government. In Singapore this usually means focus groups and discussion. Neither countries really want to deal with angry citizens (but will do so extremely harshly when the need arises).

This is in stark contrast to a place like India where pulling up bulldozers to solve problems is becoming increasingly common. Politicians will command building of infrastructure just to satisfy voters without thinking through long term consequences. Often you get projects which exist just to check of the fact that they have built something even if that thing is utterly useless once complete.