"The thing that I just cannot stop wondering is, why, knowing the perks of industry, advisers still treated us like this."

You can drop "knowing the perks of industry". There's no excuse for doing that under any circumstances, even if there is no industry alternative. I see this in many fields where grad students work in labs and are funded by grants. I wish universities would clean it up. There's simply no excuse for it. There's nothing about being in grad school that makes this behavior okay.