I heard the same thing from my friend who is also Thai. People really hate the crown prince because of his character. He played an part in the massacre of the students in Thammasat university. I have also heard that the princess is very popular and that she has the title equal to that of the crown prince. Also she is her father's favorite. I got this from website. I don't think people know how important King Bhumibol has been for Thailand. In numerous cases, he has protected the stability and peace of Thailand while encouraging democracy. He is truely beloved in Thailand because he is seen as the protector of Thailand. People sometimes dread the thought of his death becaue they hate his son. Bhumibol has acted as the mediator between the military, which is very powerful in Thailand and the students who have protested for democracy more than once. He is able to stop the military because of his position as king and because people respect and love him. His son does neither has the respect of the people nor their love, which means I honestly hope he does not become king. Also I don't see it being a problem that his sister is a woman since in SE Asia a lot of women are leaders and they are the heirs of their father's legacy. Example Megawatti is the daughter of Sukarno, and herself became president. Aung San's daughter is the symbol of Burma. Arroyo and Corazon were both daughters of politicans and both lead the Phillipines.
"Although the subject is never publicly discussed in Thailand, most observers believe that Vajiralongkorn shares none of the enormous popularity of his parents among the Thai public. This is partly because of his career as a military officer at a time when the public have turned against Thailand's long history of military rule, partly because of his irregular private life, and partly because he is seen as a cold and remote personality.
The Economist wrote in
2002: "Vajiralongkorn is held in much less esteem [than the king]. Bangkok gossips like to swap tales of his lurid personal life. One of his sisters, another possible heir to the throne, is more popular, but Thailand has never been ruled by a woman. Besides, no successor, however worthy, can hope to equal the stature King Bhumibol has attained after 55 years on the throne."