Kaos Studios has declared that they will only make the single-player campaign in Homefront 2 longer, if fans complain about the length of Homefront's campaign.
Speaking to CVG he said "I think the main thing is do people feel that they got enjoyment out of the single-player campaign and enough of it? So we'll see how it comes out and what the gaming audience has to say about it."
He also stated that the single-player is only short because they put so many resources into making the game's multiplayer.
"We also want to focus on a large-scale multiplayer game and that you get a lot of hours play out of that as well - because that's infinitely more replayable than single-player anyway and you're going to spend the bulk of your time there," he said. "So we really want to make sure that's robust and deep."
If you, as a gamer, don't feel that's acceptable though, make your feelings heard. We felt the campaign was far too short, as you can see in our review of Homefront.