I dunno. I was late to the party and bought the game after the Kickstarter ran. I never bought it with the expectation I would be getting free DLC. I think HBS can charge whatever they want for Berlin; whether it's any good and whether it's reasonably priced will determine its sales figures. But I certainly don't feel entitled to something I never bought.
It's a very simple thing. If Inxile said they would add a companion at a certain stretch goal and we reach it, and then they released that companion as DLC but charged non backers for it, how would you feel?
Some folks didn't care. Some others demanded a refund from HBS because it broke with the spirit of Kickstarter. It's fine to sell the game you made, but don't break up content and turn it into DLC non backers have to pay for. That's fucked up man. The development cost was set by the stretch goal.
Now I know Obsidian plans an expansion with PE, but they clearly said it would be a paid expansion, and you have to pledge more to get it. That's fine by me. It's very clear. HBS did not do this. They did a bait and switch after.