The general complaint is that Cambodia is under Vietnamese influence, mostly stemming from its backing of and leading the defectors who overthrew the Khmer Rouge. People today complain that the top govt officials are still Vietnamese, whether by backing or by blood, as well as many of the richest tycoons; the primary deputy prime minister (there's plenty) Sok An is often called a slave to Vietnam, and he's in charge of the Apsara Authority, which manages the Angkor complex; Sok Kong (unrelated), is one of Cambodia's richest men and ran the conglomerate that held ticketing rights to Angkor for decades; he is ethnically part Vietnamese, and because Angkor's tourism revenue was suspected to be too low, complaints about the national landmark being sold off to Vietnam were so huge that it factored in the last general election. An age-old cultural hatred is at play here, which itself comes from old empire stuff.

Because you have to dig a bit. I have spent quite some time in the area and all main officials are in close relations with Chinese. Take the PM, Hun Sen, who is publicly linked to the Chinese (by family)+ gave all the key oil exploration contracts to Chinese corporations. Have a look into the latest International Transparency report, you'll see that there are increasing doubts about his "transparency" "It's hundreds of miles from China" => since when that proves anything?