Spek, I know plenty of people who summer in the Hamptons every year for two months and have not been to Europe in decades. Check out how much it costs to rent a house in the Hamptons for the summer, compare it to the cost of spending two months in Greece/Spain/Portugal/Italy. You will see that it's not the lack of money, it's the lack of desire to stand in two hour security lines in Paris Airports, zero air conditioning in Europe, and having to buy timed tickets to visit any sort of attraction in Europe these days.
Europe is dirt cheap compared to the US. When my first son was born, I wanted to take the family to Maine for the summer, when I looked at prices, I realized that it would be cheaper to fly business class and stay in Ritz Carlton in Spain than to stay in Class B hotel in Maine.
It's not that Americans cannot afford to go to Europe, it's just most don't value what you get in Europe - European culture, heritage, architecture and food.