Interesting that you bring up Charles and Parker. Tina Charles played for Team USA in the 2010 World Championships, the 2012 Olympics and the 2014 World Championships. Not only did Tina play for Team USA, she excelled for Team USA in each of those competitions. I recall watching an international broadcast of the 2010 World Championships and hearing the announcers say that Tina Charles was the best young post player in the tournament. In the 2012 Olympics, it was Tina Charles who stood up to the Australian post players and turned around a game the US was losing. Candace Parker wanted no part of the physical Aussies in that game and was eventually replaced with Ashja Jones. Two years ago in Istanbul Tina Charles was again outstanding and, in my opinion, should have been on the all-tournament team.
I know no one is suggesting that Tina Charles shouldn't be on the Olympic team or that Charles made the team at the expense of Parker. I mention Charles as a way of asking why so many people care that Candace Parker isn't on the Olympic team. Tina Charles has contributed more towards Team USA winning gold medals than Candace Parker has yet I doubt anyone other than UConn fans would care if Tina Charles were left off the team. Why are so many so overwrought by Parker's absence? It's not like Team USA hasn't done just fine without her.
So far, Parker has played for Team USA in a total of 2 major international tournaments: the 2008 and 2012 Olympics. She did not play for the gold-medal winning Team USA at the 2010 World Championships, nor did she play for the gold-medal winning Team USA at the 2014 World Championships.
I really wanted to address the first part of your post which I find the most interesting. People need to remember that this is TEAM USA. Anyone remember Cappie Pondexter opting to go to Fashion Week in New York instead of joining Team USA for practice and tryouts the first couple of days? She was left off the 2010 USA team that went to Prague.
Compare that to Parker. Yes she had surgeries, but she made sure to have them done so that she'd have time to play overseas, and earn lots of $$... but it was at the expense of Team USA and the World Championships in Prague and Istanbul. In fact, she was playing through the injury in 2010 in the WNBA until her team tanked and decided to take the rest of the season off to have the surgery and recuperate.
I get that players have injuries and need surgery. Can't blame them for that. BUT if she chose to schedule the surgery so that she'd miss the World Championships in 2010 and 2014, BUT would would be healed in time for the lucrative overseas seasons, I can see why USA basketball might be miffed. Cappie was left off the team seemingly for her transgression at NY Fashion Week. Choosing to pass on Team USA twice so she could make more $$ overseas seems like a valid reason for Team USA to pass on her now in 2016.
People are overwrought about Parker's absence from the team because they believe her to be one of the best individual players in the world. She may very well be, but Team USA is all about the TEAM. It's about sacrificing individual goals, etc, for the betterment of the team and our country. If the committee felt that she had consistently put her personal career over Team USA, I can see why they would have done what they did.
Instead of blaming the US National committee and Geno, maybe people should take a harder look at what Candace did for Team and Country and see if her absence has more to do with her past actions.