Not to brag or anything, but I did read the book. Well, okay, here's why it's not bragging, I only made it about 50 pages into the book, and then I had to stop. People may assume that it got too emotional, and I just couldn't push my way through, but that is not quite the case. The reason I stopped reading is that I found the main character to have no redeemable qualities. He basically just seemed like no person I would ever want to encounter in my life.
Am I saying that he was a bad person? No, I am just saying that he would be a bad person for me to encounter. His ideology is far different than mine, and I likely wouldn't find him enjoyable. He was basically like WWE's Zeb Colter character in that he was an extreme Xenophobe, and without the catchy saying of, "We The People." That type of person isn't nearly as endearing in real life.
But, shit man, if you say anything negative about this guy, people blow up about him being a hero. What he did was incredibly difficult, and there is no way I could do something like that. It would undoubtedly change me for the worst. I have to respect that, but I don't respect it any more than any other military member. It's incredibly brave, and that is why I had ZERO interest in joining any branch of the military. People who just call him an awful person without understanding how that experience would affect a person need to take a step back and think about what he went through.
Speaking of people who think he is a hero: To me (and probably by definition), a hero is someone you want to emulate. So if this guy is your hero, you can join the military if you want. It's super easy as long as you don't have a disability, you're basically good to go. The people who say he's their hero should probably slow their roll.
Overall, there are aspects of Chris Kyle that deserve respect, but saying that his actions in the military make him above reproach is insane. People really want to take hard line stances with their opinions on this movie and Kyle as a whole, but like most things in life, you're best off understanding that the scope of the issue is in the gray area.