I definitely understand what you're saying, but to me all that stuff is boring. All of the "beautiful in its simplicity" stuff that you find everywhere in Japanese culture just gets plain boring after a while. That's just my opinion. But it also probably stems from the fact that I've been in Japan for 7 years, so things are bound to get boring regardless.
Another thing to note is that I started eating sushi only after I came to Japan 7 years ago. So the only times I eat American sushi are whenever I return, basically once a year. Perhaps if I moved back to America my appreciation for sushi in Japan would increase.
But avocado goes extremely well with sushi in my opinion, and you'll never find that in Japan. I also enjoy all of the different sauces that are used in American sushi. In Japan, you never get anything besides wasabi and soy sauce, unless you order eel. I just think American sushi is more creative and bold, and has a wider variety of flavors. A lot of the rolls look pretty badass, too. Over-the-top, absolutely, but at least they aren't boring.