All one would ordinarily do to check call strength is look at the home screen. For me the dialpad is a very infrequently used app, and I rarely use it to make calls.

In any case, why are you so hostile to the idea that Apple was being intentionally malicious? If I were trying to discredit a competitor's product, I too would choose the most unattractive space I could to highlight it. Given that the signal strength is shown in most apps, you certainly have a wide choice.

That is the app where (for most people) signal strength matters most. To me, it seems contextually relevant.

It's just less simpler than the home screen with a nice background, however, there is no reason why anyone would open the dialpad to carry this experiment.