I've thought this before. I don't know if there's a good reason not to. Plus, apparently the Super Bowl is watched worldwide... But I don't know how that is since it's played in the middle of the night and/or on Monday in a lot of the world.
If there was a "world" all star team that played versus US born players it would do more for international marketing. World all star weekend. Non US born player plays on world team. Mostly Latin Americans and Asians versus US. Puerto Ricans are a problem politically since they can't figure out what they want to be.
It seems like its a national holiday already, it starts on one particular day but Americans need a week to celebrate it because we're all soooooo fucking busy we can't seem to bothered by celebrating anything on the day it occurs. We celebrate it on a day that's personally convenient.