In the Great Lakes area, walleye (pike-perch), perch and whitefish are among the most popular and best-eating species.
And there you have your answer. Freshwater fishing is proscribed in the UK, it's more a genteel sport than a hunting mechanism. There aren't the stocks that you have around the great lakes, and population density here would result in overfishing very quickly if it wasn't ultra-regulated. 80% of fish caught in reservoirs get thrown back. Live. The thrill of the catch, see?
But the distance to the coast for most of us is relatively short - certainly by US standards. And mackerel fishing is just too
bloody easy :)