The first couple of gits you quoted did have a toehold on a valid point, which is that regardless of who strikes first, if we hit them, they will indeed want to hit us back, it's just human nature, after all. However, they fail to carry it through to the next set of logical points that complete the thought -
1. 'WE' are on 'OUR' side, not impartial observers, nor playing for 'Them;' and
2. That natural human desire for retribution can be quenched by beating 'Their' asses so bad they throw in the towel off their heads.
This is the major part of the equation they lack in their heads. As far as they're concerned,
we're the bad guys--nothing I need to tell you.
One of the later blitherers blithered about how "1 million brown people"--sure, they're all "brown," whatever the hell that means, and it's not like we get to choose our enemies' skin colors--is somehow more than enough payback for 3000 Americans. That goes to your second point--it's not just, or even primarily, about retribution. It's about crushing them to the point where they can't attack us any longer.
Obviously the schmuck would be
so pleased if the jihadists somehow managed to "even the score" (and he doesn't seem to have noticed that they're still trying). And that is the most appalling thing of all about the lib mindset (well, "somethingset"; they don't really
have minds, as such) when it comes to the US protecting itself. They're happy when the enemy succeeds.