Is it surprising to people that non-democratically elected leader to be loved? You have to remember that Thailand is an Asian country with Asian cultural beliefs and perspectives. These differences resulted in our inherent respect for elders, supervisors, rulers, etc. And our strong belief in hierarchy as opposed to meritocracy. These demonstration of respects would hold for people that you respect regardless of legal precedence. It is a bit hard to describe these actions in Western context. But with growing Western influences, these views have slowly altered closer to a Western one.
Generally and historically speaking, the public have been more or less given one-sided information on the institution on what good the King and Royal Family have accomplished on the behalf of the country and its people. There's a long list of accomplishments such as New Theory of Agricultural