If you hired an ad agency to run radio commercials in Texas and then get a bill saying "oh by the way we found cheap ad space in Tokyo so ran some there too, here's the bill", you'd probably question your relationship with them.

I understand it's not the same thing, but it sure smells the same

The blog author didn't read the docs. He signed up for a relationship and just assumed it would be different and now he's complaining about it. As I mentioned in another comment: From Google AdWords help docs it says "By default, location targeting includes both physical locations and locations of interest".

It seems logical that the chance of you buying their chicken is much lower than someone actually in the US. Why should they pay?

My guess would be that you're making the assumption that I'm looking to buy chicken. It might be the case that someone is just researching "US chicken market"?

And why would most chicken ad publishers want to show ads to those people? I imagine most of those publishers are selling chicken, not information about the US chicken market.

If I don't do business in Turkey, and I pay for the clicks, I should easily be able to exclude Turkey (without having to write a blog post and consult an inside source that most could never reach)

Only if the advertisers choose to have their ads served to you. They don't owe you ads.

There’s a difference between publishing ads for a product that is related to US chicken and publishing ads in the US for chicken.

I believe it’s clear in the Google publisher dashboard that you are targeting your ads to appear to people in the US, not that your product itself is relevant to the topic of the United States.

I think Google has some knob: point of interest vs physical location somewhere inside UI.

Only if the person who was paying for the ads wanted to show them to you in the first place?