The corporations are all bad.
Atlas is just an ally because of story reasons from TftB. if you played BL1 they basically just stepped into Dahl’s footsteps after they left.
Jakobs being nice borders on a retcon. It’s a complete turnaround from how they were in BL1, they didn’t cared one bit if workers got eaten alive.
Tediore, well they may not be as eviiiil as the others but like said they sell dangerous malfunctioning weapons as a feature. Imagine Apple telling you “well duh, our phone might not work but you can still throw it at someones face! So buy it anyway”
Also there is some difference between:
Mister Torgue who is a nice guy (by Pandora standards) and Torgue as a corporation. Death isn’t enough, the enemies have to die in the most gory way. They also sold weapons directly to the bandit clans in Borderlands 1.
Dahl and the Lost Legion. The latter is a rogue unit genuinely trying to avert the things that Handsome Jack would set in motion.
Also they might all do different things like Hyperion advertising tourism, Atlas producing food etc. but they are also pretty much the government because a central one doesn’t exists anymore. In the Borderlands universe the corporations rule everything and at their heart they are all still weapons manufacturers. Like @KauluMaisas said they all profit from violence…
And so is Marcus
And the Vault Hunters, sure they might thwart an cosmic invasion here and there but at the end of the day they are still just mercenaries working for the best gear.
So no, in no way are the Vault Hunters bringers of peace although they might make life better for the people of Pandora, along the way.
Sorry that this post is already so long but one thing that I find kinda relevant:
One of my favourite moments in the series is actually in Borderlands 1 where you start wiping out a bandit clan, thinking your helping the people but it ends up just ending in a takeover from another even more violant clan. You then have to clean up the mess you caused, so that Helena Piers even trusts you.