The bottom-line performance of any government is measured by its success in managing the economy and putting money into its citizens' wallets. In Thailand, as long as the current ruling regime can deliver on the economic front, it can remain authoritarian and generally safe from mass uprisings against it.
Every nation has a different history which leads to diverse governing regimes. China has a past of continuous authoritarian regimes to hold its vast population together. If wealth was too concentrated, the system broke down and failed, ending up with civil wars and competing fiefdoms.
For a semi-authoritarian country like Singapore, its former prime minister, Lee Kuan Yew, set up the nation under the principles of Confucianism and Christianity, together with a controlling model of democracy, bringing the tiny island state its very own economic miracle.
