Germany is mostly pils, heff, and radler. The USA has more beer variety, maybe it's more difficult logistically? Companies in the USA do have a beer man, never heard of individual houses hiring one.
No, it's just that for as much that has changed in America since its founding, being a bunch of Puritanical tight asses is still kind of encoded into our societal DNA.
It has been a battle ever since. The area I live in only recently allowed the sale of liquor in restaurants and bars and still does not sell liquor by the bottle. There were many movements that had influence so perhaps it isn't fair to lay the blame solely on the Puritans, but they did have great influence in regards to alcohol in the USA and the parent isn't wrong, but has certainly omitted details.
For example, I can't purchase wine to be delivered to my home over the internet in my state.
As for beer selection, as in the US the major brands are of a limited nature but there are many small breweries. All subject to the Reinheitsgebot but I doubt it really cramps their style.