Why do Thai people get so judgemental when people from other countries make their food?

I am serious, I am so sick and tired of Thai people being so judgemental when people from other countries make their food. My wife is American and she can good great Thai food. However, Thai people want to dwell on the ingredients until they find something to gripe about. I could have a Thai person make pad thai and then put in on the kitchen table and lie and say my wife made it and then Thai people would say it is not authentic. They seem to equate "not authentic" as anything made by someone who is not a Thai. Honestly, some Thai people have no idea about their food. All they do is go get the food from a food stall, they don't even cook, well most of them don't.