To be quite honest, I am on ascian's side for this. We get a brief look into their lives through Emet Selch's eyes. We get to see a portion of their society in the tempest and what their society accomplished. While some of their experiments were grotesque, they really don't vary much from what we see in current day real life experimentation (that which is public information). All the ascian's want is to live in peace again with their family and friends. From my perspective they see us, exactly the same way we see them, as villains trying to destroy everything they know.

To tie this in with Thanos, his idea was logical. Get rid of half the universe's population to benefit the other half long term and potentially short term. The method to which he carried it out was also the most logical choice, as it was truly random; he did not pick and choose who lived and who didn't. The method he implemented to achieve this was where Thanos screwed up. People are going to fight back if you simply tell them you will take away half of all living things, all while killing them getting the items you need.

I understand why the scions don't want the rejoining. I know that innocent people would die while not so innocent people would also die. My problem with the logic the WoL and scions are using is that the logic is flawed. We have only seen 2 worlds in the ffxiv universe. We know some of the worlds are already consumed, and are no longer able to produce or sustain life. What we don't know is the other worlds that are still life bearing. What is going on in these worlds? Perhaps they are suffering immensely from the worlds being separated? Perhaps they are fighting to rejoin the worlds as well? Time will only tell, I for one am looking forward to how the story plays out.