I think WWII was felt more on the home front than WWI in the US, which is why we don't remember it as well. The sinking of the Lusitania didn't have the same impact as Pearl Harbor. We didn't go into the war recovering from a major depression. Life was pretty good in the US at the time. Our soldiers went off and fought a war. Some came home, some didn't, but it wasn't the same level of mobilization of industry and patriotic fever at home.
The Brits, OTOH, got slammed by WWI. Villages were populated by woman, children, very old men and, as time passed, those too injured to return to the front. Almost no healthy man of average age didn't end up in that war. Nobody escaped the impact of the war. Their whole world changed, almost over night.
Plus, they were basically lied too and they knew it. "It'll will all be over by Christmas." The truth of the conditions of the war was covered up very badly by those in power for a long time. It wasn't really until the wounded started coming home and talking (or not talking, as was often the case) that the truth of how badly mismanaged and misguided by the people running things was known.
So it's not surprising that the Brits have spent more time on the subject. It holds a relevance to them that it just doesn't have over here.