Why is the strong 1NT so prevalent in Bridge?
I am no bridge historian, but wouldn't the underlying answer have to do with the underlying  "path dependence?" This is a standard: Most people in Britain use weak 1 NT, so people in Britain first learn weak 1 NT. Conversely, most people in the US use strong 1 NT, so most people in USA first learn strong 1 NT.

The main idea of path dependence is that there doesn't have to be some grand "reason" that a standard develops. A standard would only get undermined if it was radically inferior (e.g., people that play one system win way more often, ceteris paribus) . I'd guess that Truscott's book has some story... which gave a kernel of advantage to each system in different countries... which led to a "lock in" of each standard in each country. 

It's not like the average player in the US plays often with people from Britain. And there's not this bias at the highest levels of bridge, right?