Naw, Americans are fine with pain. We have one of the most brutal wrestling cultures, our favorite national sport is football which is really, really grueling.
Judo isn't popular in the US because the organizational structure is so bad and the overall level of coaching is so low that it's really hard to get involved with a good club (because there aren't many). You have to work so hard in the US just to get quality instruction and training, and even if you do care enough to do that you're going to spend all your time going to tournaments that are mostly poorly run, and god forbid you have success and get good because then you'll have to fight against the national governing body (assuming you're affiliated with the right people and even have a chance to ask) to get funding to ever compete at a higher level. Most likely you'll just be poor and no one will know who you are or what you've done unless you happen to win an Olympic medal, in which case a small community of grapplers will remember you for at least a few months which will be worth ~$0 to you. Oh, and in the US no one is willing to pay much for Judo instruction so good luck making a career out of your main life skill after your competitive career is over. The only 'sport' I know of that is popular and lucrative in the US that lacks organization at the scholastic level is racing. As in, NASCAR. All the other Olympic sports are either super niche sports (in America) like badminton or weightlifting where we get crushed by nations with state sponsorship, or vanity sports like Equestrian that are the province of the very rich who can afford to compete in the rarefied air of hobbies that require a horse. I would largely lump a lot of the winter sports into that category as well, though we have traditionally done quite well in some like figure skating even though they aren't heavily state sponsored.
