Different culture, so I don't know about any of those sports, nor does hardly anybody else in the US. People in the US love the celebrations, it adds to the intensity of the moment and our "swag" culture. Believe me, I am an "act like you been there" kind of guy, but most people don't want to see a Barry Sanders' hand the football to the ref routine. As for long-term viability, the concussion debacle/issue will be more part of the NFL's drop in popularity. I think less kids will play it and better athletes will play other sports.
Some celebrations can be hysterical to watch, especially when they are clever. Most aren't though, so I am personally ok with the NFL limiting celebrations....I hate seeing cocky players (cough cough Kaepernick) celebrating themselves in the endzone and acting like they are God's child. It took more than just the individual to get those points and they should learn some respect.