They may not care about openness directly, but openness usually leads to more possibilities. Consumers will care about the new features and possibilities that openness welcomes.
But I think it's an issue of degree. The iPhone IS OPEN to a large extent. Enough to produce 75,000 applications after all. The question really is "Do consumers care about the openness that separates Android from the iPhone"
But the openness doesn't affect consumers directly. It affects developers first. So a more open platform gives way to more possibilities. And the iphone platform has a $99 fee, which is probably a deterrent to hobbyists. Then on top of that is the closed app store subject to Apple's arbitrary approval. The closed store is probably the biggest hinderance of possibilities.
You can already see examples of Apple losing features because of its closed platform: no google talk, among other things.
And I think it's only a matter of time the rest of Android get's polished up. But the main point is that while Apple has primacy and great design as it's advantage, Google has the openness as its advantage.
They may not care about openness directly, but openness usually leads to more possibilities. Consumers will care about the new features and possibilities that openness welcomes.