There are various reason why people whine and complain. Most of this reason is to feel important and to be taken seriously.
See any book by Dale Carnegie.
... Also whiners and complainers do not make a whole not of friends nor allies either.
Moving on. I believe Steve did pretty good. It's a free market out there. No one is holding a gun to your head and say you must buy and use Apple products. There are other products out there if you don't like Apple's.
Go return your iphone4 if you hate it so much. AT&T should have no problems with the refund as well, as they work directly with Apple on it. (They get to return their returned stock back to Apple too).
And those who thinks a company can troubleshoot, and design, test, and come up with a end-all fix have never developed hardware, software, or work in support ever. For a problem like this, it may take several attempts to fully understand and fix the problem.
The symptoms/issue have been identified, but the true root cause have yet to be truly understood. There are theories by people who believe they are important/experts that it is a hardware design issues, but in truth, to confirm and verify this, then come up with a solution will take a while.
Until then, they identified a bumper case should alleviate the issue, and decided to give away 1 for free.
Apple engineering is still working at understanding what the real root cause is, so they can experiment with various fixes to find the best solution.
If you've already think you know what the problem is better than Apple's team of engineers, and you think you know how to fix it, then you really should not be wasting your life here whining. Instead you should be working as senior or lead engineer some place earning 6-digit+ salary.