I don't think they did this intentionally to get people to love them for fixing the problem at all. I think they knew about the problem and then put it out anyways because Apple, and especially Steve Jobs, are incredibly arrogant and figured they could get away with it because, well, it's an Apple product, and Apple fanbois will line up to buy any new iProduct even if it isn't good. But to the general public, this is really tarnishing Apples omnipotent image as being able to do no wrong, and the initial responses made them look even worse.
"It's not the phone, you're just holding it wrong!"
"It's not the phone, the software had a glitch, that's all!"
"It's not the phone, it's the AT&T network!"
"OK, it's the phone, have a free case."
I think Apple felt really rushed to get the iPhone4 out because of all the momentum Android was building up, and ignored smallish problems in an effort to get it out with as many "innovations" as possible. And they got an epic backfire from it. But this is just my speculation, and we'll never know for sure, because Jobs and Apple will never admit to anything unless there is overwhelming proof against them, and even then, it's iffy. Only thing we can hope for is someone who gets fired from Apple and is bitter with an axe to grind AND has knowledge of this whole fiasco. But Jobs will probably make sure they had an unfortunate "accident" before they got to the press.