Monks let animals wander everywhere. Monasteries are de facto sanctuaries for lost pets and their descendents.
They have habits hardened from 2600 years of tradition. And those traditions, some very odd to us, are blended with local customs and attitudes as well political expediency.
Fortunately the tolerance is a seamless garment. In spite of a deep sexual conservatism, fairly rigid social expectations, and a history of sexism, Thais don't judge much.
Thais are sensitive to behavior that deviates from norms, and notice it, but they don't seem to be driven by the hate and fear many Westerners show toward various outgroups like illegal immigrants and ladyboys. They might smile or raise an eyebrow, but the immigrants and transsexuals are treated pretty tenderly, most of the time.