The Nike ad says "Believe in something, even if it means sacrificing everything." (emphasis added by me) Seriously? Sacrificing everything? Kaepernick did not sacrifice everything. The men and women that died in the line of duty serving their country or their fellow man while wearing the uniform of the US military, or a firefighter's gear, or a badge and blue, they sacrificed everything.
There are a number of posts here that rightly say that sacrifice is not a competition, and one even properly says that sacrifice is not binary, that it's a spectrum. However, the end point of that spectrum is the full and final measure of sacrifice - your life.
There are many that have done what the Nike ad says, and I completely agree with the statement in the ad.
However, putting the picture of Kaepernick over top of that statement just ads insult to injury given that it illustrates the very reason why some (including me) do not support and are offended by the disrespect to those that truly sacrificed everything for what they believed in - freedom, liberty, and our Constitution which they swore an oath to protect.
Some folks just don't understand, and that's okay with me. I don't expect everyone to understand, or even care.
I don't necessarily agree with what Ms. Kyle said, but I can understand why she feels that Nike disrespected her husband and others like him.