Reeve didn't care about politics before and did not care much more about it now. He would let others speak about their grand theories and reasons, nodding respectfully once in a while. This made some of the groups mistakenly believe he agreed with them. Combine with is reliable attitude and fighting prowess, that made him get along with almost everyone.
If prompted enough to give his own opinion though, his answer what simple. Humanity fell because there was no more heroes to protect it. Why that was exactly? He did not know, or really care. Were the old heroes in hiding waiting somewhere? Are heroes only born at certain generations? Had Humanity gotten lazy, complacent or corrupt? Doesn't really matter. There was a need for heroes now and he would be one of them.
So he kept training and challenging himself. He would reach the heights of the heroes of the past or have a glorious death along the way if so was his destiny.
OOC:
So he would lean more toward the 3rd group personally.