@Yo***
Thais are seen as a higher risk to become a public charge in USA vs the other countries you mention (Japan, Korea, etc). And that's the only metric if you want to call it discrimination. The other 74 countries in the same boat.
It is in best interest of each country to apply measures that will not put an illegal strain on the local tax payers. Thailand does the same. They treat different countries differently based on their analysis of risks of a person becoming a public charge. A person from Myanmar will be treated differently than an American for Thai entry. Should Myanmar people scream foul and discrimination by your logic?
BTW: it's around 4% and growing, that is, the Americans visiting Thailand. There has been a sharp decrease of Chinese tourists in 2025 and the local businesses were bitching blue murder to the Thai Tourism Authority, much so that same authority postponed a fare increase on MRT/BTS which would also affect local citizens.
While the knee jerk reaction to US visa suspension is to implement a similar restriction for Americans will only serve to harm local Thai businesses. It is what it is.
Wait around long enough like 3 years (😉😉) and things will go back to normal.
Sorry for the long drawl.