I have to agree with David. Americans aren't lazy, they're just used to filtering out what works and what doesn't. You also have to remember that the US has been innundated with immigrants, all with different languages, since before we were a nation. It's only natural that our version of English would be a bit more...colorful than the Queen's English.
Heck, my home state has been part of the Union for over 200 years, but it wasn't until my parent's generation that a majority of people spoke English as their first language.