I don't think so. Every martial art, to a certain extent, has to adapt to the mentality of the host region. Americans want belts. It gives a psychological boost to have a tangible reminder around our waist of how far we have come, and it certainly is harmless. Belts give us something to aim for. Otherwise, we'd have no real goals to set.
That's why we have grades in school. Try to imagine going from K-12 without grades.
As for uniforms, they give us the identity of being in Taekwondo. Without them, I think the mindset would be drastically different. People just wouldn't take it seriously.
School grades are not the best comparison to martial arts, though I do follow the analogy. In school, we don't wear belts to indicate that we're in high school; its mainly a function of age and socialization. And unless you pass, you don't go to the next grade. But most people will pass in school and go onto the next grade, and the grade they start in is determined by their age; young children go into kindergarten, eleven year olds are middle school age and fourteen through eighteen is high school age. On the other hand, I started kendo in my thirties as a white belt along with my son who was eleven. Martial arts for most people is like night school: you want to take it so you do, either to gain the ability to defend yourself or simply because you just want to. Or in the case of kids, its an activity that they do for the same reasons, or because their parents feel that it will help them.
And in reality, do Americans want belts? Or have they simply been told that they do for so long that they simply expect it with martial arts? I spent quite a bit of time at the fencing salle. We didn't need belts to get better. We had ratings that went up and down with competition, though if you didn't actively compete, you didn't have a rating. Boxers don't wear belts to show their level. They're rated by weight and competition record. Same with wrestlers. You can't tell me that Americans need a regular visual reward to want to do well. All people, regardless of their culture, need goals. Nobody needs the belt to have goals, and that includes Americans.
I do think that the emphasis on younger kids doing martial arts as if it were gymnastics is what has brought about this perceived 'need', as children, regardless of culture, need more tangible motivations.
Regarding uniforms, I have, very sadly, seen plenty of kids and some adults who don't take the class seriously while wearing the uniform. Certainly, I don't think that the uniform should go. Just as we have appropriate attire for baseball, swimming, tennis, or cycling, the uniform is appropriate attire for a traditional martial arts class. I was only commenting that the crossover and V-neck uniforms with vented sides would look awful silly without some kind of belt.
Daniel