Much have been discussed on this topic, the arbitrary figure of 10 million is reached top down by the PAP based on optimal economic sustainability supported by an achievable land density.
Singaporeans have reacted, like Roy Ngerng, providing the bottom up sentiment. What is left is now the skill to balance, the political skill to achieve equilibrium.
Over the last decade, PAP has pushed the limits of letting foreigners in, failing to balance the infrastructure needs and social tolerance. As such, it has resulted in a heavy backlash.
To pull back, we have a problem of stopping a runaway economic situation towards 10 million! For instance, over the years, due to optimism of more population, there are many eateries than before. These generated demand for service staffs. When PAP reduce inflow of foreigners, we get complaints of labour shortage.
All these problems arise due to imbalances of the economies. We will have to let some eateries to fold then, people will realise that over exuberance is not desirable.