Wasin was not entirely wrong. Well I accept that trying to kill all the heirs in order to sabotage their parents…
Yes.. And He believes that every prince views the crisis in a way that benefits him only. Prince Rachata sees the problem as a result of the hospital in his city bringing in more patients and thus wealth, and the same thing for Ava's father, the pollution will benefit him because the need for air purifiers increases. Only Prince Tharin and the heirs feel responsible and want to actually solve the problem.
https://www.youtube.com/watch?v=NokvN2ndceo