1. He refuses the job while he is still in recovery, and tells Idris' character as much, until he learns it is something he was being asked to do by his ex-wife, the one he had left with their dying son. It has been 9 months since the events on the bridge at the end of Extraction, explicitly stated both at the end of Extraction and by Yaz in Extraction 2.
2. He accept the job for that very same reason: family. Guilt.
3. A prison riot ensues and the guards are fighting the prisoners and versa, as well as the prisoners turning on each other and on Tyler... it is not a 400 vs Tyler scenario. They're fighting each other, not waiting to fight Tyler, and you can easily see that. (and yes, movie tropes of like "why didn't they all gang up on the hero at the same time?" or "why didn't they just shoot the hero when they had the chance instead of talking?" bother me too but that's just how movies have always been made. That wasn't the case here though.)
4. The Georgian people are not the bad guys; a radical faction/gang of organized crime, the Nagazi, are the bad guys and it's really a story of revenge from the leader of the Nagazi for the death of his brother.
Those are just the facts. If you're going to criticize, the facts about what you're criticizing are important and skewing them to make your point only makes your point less valid.
Now that being said, and with all the facts in line: I didn't enjoy it as much as I enjoyed the first one. It's a perfectly competent and entertaining action flick that should probably win some sort of award for cinematography but it's not a deeply nuanced film that will make you care very much. The first one made me care about the story. This one, not really. But it's fun for what it is. That's my review.