Hmmm, so you are generalizing every American because Beverly Hills Chihuahua and Paul Blart:Mall Cop were #1 box office movies. After all, we dumb Americans can't get the subtle nuances of Jerry Lewis acting "wild and zany", and his canon is so far above that of those movies you mentioned that I should be arrested for mentioning them in the same paragraph.
Well since it just came out recently, let's look at the box office figures for Paul Blart: Mall Cop (a movie, by the way, that I have no intention whatsoever of ever viewing). Last weekend, which was the movie's first, it made a little less than $32 million ($31,832,636 to be exact). After doing a little bit of research on Beverly Hills Chihuahua (released 10/3/08) I see that it made a shade over $29 million ($29,300,465) it's opening weekend. In this day and age, when the average price of a movie ticket is $7.20 per person I think it's safe to say that while these movies were both "#1" movies, that $29 million and $32 million are not exactly mind-blowing numbers for opening weekends. In fact, Beverly Hills Chihuahua was helped by the fact that it is a children's movie made by Disney, and parents are always looking to take their children to movies that will keep their interest. Both movies are in fact rated PG, which again is going to help to their numbers because it is safe to bring your children to them (for all I know PB:MC can be a kids movie too, I've just seen a commercial or two and decided I would pass).
Let's also factor in the release dates for such movies. October and January are hardly big movie going periods. If either of these films went up against The Dark Knight during the summer months they would have been slaughtered. However, with the relatively small cost of making films like these and the decent box office numbers providing a big return you can at the very least expect straight to DVD sequels in the future. That's why all of those asinine "spoof" movies get churned out at clip of two or three a year: they are cheap to make and generate a good profit.
A quick peek on IMDB shows that Beverly Hills Chihuahua currently has a rating of 2.4/10 while Paul Blart: Mall Cop comes in at 5.5/10. I'd hardly call these glowing reviews from the American Public. So please, if you are going to make elitist blanket statements like "...Americans truly like flat out garbage..." get your facts straight and try to know what you are talking about.
What you don't understand is that I would rather take a hot lava enema than sit through a Jerry Lewis movie from start to finish. Once he comes on the screen and starts doing his lame, tired act I zone out immediately and if other people are watching the movie I leave the room (if I am alone I turn it off). I do not have low enough self-esteem to make myself sit through a Jerry Lewis marathon, so there is no way I would "laugh until I cried".
I don't like Jerry Lewis, I think he's unfunny and stated my opinion. If that opinion offended you, tough shit.