It's difficult to question Apple's honesty here without it becoming an ad hominem attack, but it's difficult for any reasonable person to imagine that somehow throughout the last three years of having a product in market, with a carrier who is notorious for dropped calls, the whole signal-strength-to-bars algorithm hasn't come under some scrutiny. I mean, the first question you ask someone when they complain of dropped calls is: "how many bars did you have when the call dropped?" It's difficult enough to get accurate information from users without feeding them erroneous information.
I don't think it's as clear cut as Steve Jobs instructing his teams to pump signal strength reporting, but if they were given a selection of algorithms to choose from, and they chose the one that reported "more favorable" results, then that's on them.