I just saw a episode about Angkor Wat on Travel channel where the narrator totally misrepresented the purpose of temple and shiva-lingam. He made the Khmer look like some kind of savages beating slaves to build a the temple to gain supernatural powers from the lingam. In reality the Angkor Wat was a Vishnu and later a Buddhist temple not so much of Shiva temple.

Foreigner tax can be seen as discount for locals. This is a common practice in USA too where locals get discounts and often free entry into the places like Botanical gardens, public parks and so on. Hunting licenses in your home state are around 10x cheaper than another other state in USA. All the H1b, Gc petitions can be seen as a "foreigner tax". US government forces H1Bs to pay social security but does not allow them to benefit from it. That is far more significant tax than what Cambodia might charge the occasional tourist.