As Wyatt wrote in Thailand: A Short History (2003, p.231): “… many would have agree with King Prachadhipok’s judgment that a move toward democracy in 1932 was premature.”
Consider the number of coups d'état, both successful and unsuccessful, plus several chaos since B.E. 2475
Even a non-military : Pridi Banomyong attempted a coup
(in 1949 against Phibun's dictatorship, but failed)
Now, we are in 2559; 84 years since 2475, the Thai democracy is still jumping up and down!
Gaps between the elite and the peasant, the rich and the poor are still wide!
and many other failing indicators