Buried everything is not unusual in the US. Roughly 20% of power lines in the US are buried. Contrast that to somewhere like Tokyo, which has less than 10% of its power lines buried (which shoots a massive hole in your theory about that having anything to do with whether a nation's infrastructure is adequate). It varies from location to location in the US; where I grew up, everything was buried. It's bizarre that your supplier would in any regard be surprised by such a thing.