Is it worth going to US Open?

I am wondering why the US Open attracts so many people that don't even have a chance of finishing in the top 10 or so. I understand there are class prizes, but i have been to many tournaments, and it is always almost impossible to get a class prize. Also my July supplement is 2001. This means I will be competing with people all the way up to 2199 for class prizes. I looked at the pre registration list and there are so many people that aren't even 1500 playing in the tournament. Why? Should I go to the Us Open? Should I do it just for the fun of playing 9 rounds of chess with great long time controls, and perhaps be able to play some high ranking players? I am fine with that being the reason for going, but I need a reason. I have never been to a tournament where there is only one section, and the 2700's are in the same section as the 700's. Can someone help me out? Also I am thinking about going to the worl open, but I would have to play in u2200. Would I be a complete moron if I did that? 

It's worth going to, in my opinion. If you enjoy chess, the experience is priceless. High - Stakes OTB also improves your chess much quicker. 

I'm going in order to play some strong players and compete for a class prize (U1600). But it is mainly to have fun playing chess!