The speaker argues that audiences should use Thai brand products for several reasons:
1) They help improve Thailand's economy and export numbers have been continuously increasing.
2) They provide jobs to local people through initiatives like OTOP which promote unique handicrafts from villages.
3) They encourage the use of Thai wisdom through traditional crafts like Benjarong ceramics, nielloware metalwork, and silk weaving.
4) Many Thai brands offer high quality, stylish designs, and reasonable prices in industries like clothing, jewelry, and furniture and have been successful in both domestic and international markets.