Current U.S. population: 301,256,099
http://www.census.gov/main/www/popclock.html
Military-eligible population: 109,305,756
Total U.S. Armed Services personnel: 2,685,713
Active U.S. Armed Services personnel: 1,426,713
http://en.wikipedia.org/wiki/Military_of_the_United_States
0.89% of the U.S. population, or about 1 of every 112 people, serves is some branch of the military.
0.47% of the U.S. population, or about 1 of every 211 people, is in active service.
These figures increase for the military-eligible population.
2.46% of the military-eligible U.S. population, or about 1 of every 41 people in this category, serves in some branch of the military.
1.31% of the military-eligible U.S. population, or about 1 of every 77 people in this category, is in active service.
How many people in that photograph are even eligible for military service?
There are maybe 75-80 people in the photo, so it should not be unexpected that no one pictured is either currently in the reserves or the active military.
This is not a good argument to use for the Bushes being unpatriotic and/or cowards.
The vast majority of people in the U.S. have not and will not serve in the military, provided that the current percentages are maintained and a draft is not enforced.