Dirt murderers all. Hail Advent. Mine the things.

Who needs gas when you can kidnap an Angara and have electricity?

I really did not give much thought to the 'this is bad for the environment' reason. To me it was an issue of exiles vs Podromos. Advent turned its back on the Nexus and this was a golden opportunity in the game to explore "screw over the exiles" vs "lets try to bring them back in the fold" in a meaningful way. Much better than Vetra's brat sister and her holier than thou loyalty mission (really hated there were no consequences for her in that mission).

I will be honest, the theft of supplies and the Advent water situation were actually the best side missions for me, and I spent a lot of time thinking about those decisions even though I knew it was no importance. To me it was exactly the kind of dilema I could sink my teeth into. Talking about the environment the way they did just ruined for me. Though as Devil's Advocate you can say that natural gas would have created a dependency and made colonies create their infrastructure around exploiting it, and thus lead to looking for more natural gas - but there is no evidence the writers had this level of depth when considering the option.

In the end I did not help the supply thieves or Advent. Advent were decent enough but I felt applying pressure on them was the way to get them to return to the fold. Hoping there is a DLC to expand on this. As for the supply theives, I just felt stealing supplies was not the right way to express regret for leaving the Nexus and turning to piracy. I am sure people who read the book have a different perspective, but thats how I chose.

I believe the Advent scout just really wanted to keep the water flow for their colony first and foremost.. and supply the Nexus outpost limited water in trade for the natural gas. They hold the cards and some type of economic system in place to keep Advent secure. Also, I don't believe they have the equipment currently to do many different things with energy without any real tech but natural gas might be simple enough for them.

I really screwed up their plans. Now, they have to offer our outpost something in return. Lol. They have no leverage.

I would side with them just on general principal, for having such a thinly-veiled social/environmental issue as a quest.