At first I thought this was a strange question. (no offense lamallcool ;-) I think it speaks to the diversity in the JW "mindset" & "conscience" in various parts of the US & world. I'm my area when I was an MS, groups of us went to the local US Airforce base for the annual airshow. It was not a big deal at all, and I never heard any murmuring about it. I think it's the same idea that witnesses can 'allow' themselves to go into old churches in Europe to "appreciate" the architecture.
We also went to a , MS house on the 4th of July...he had a great deck with a view of the fireworks. I was fortunately in a very liberal hall...we even had a local needs once on the "friends" (some of them) imposing their strict conscience on the activities of others....but I'm sure in smalltown, central USA the very opposite talk was being given "counsel your brothers when you see them enjoying worldly entertainment" lol. Crazy cult.