You obviously don't understand how prepaid plans work.
For AT&T's gophone, you don't need to have a credit check done at all. All you need to do is sign up for the plan, there's no credit check, there's no deposit, nothing.
Prepaid plans have nothing to do with how good or bad one's credit is.
AT&T wants you to think that you need to sign up for their two year contract, however it's not necessary. For those who use their phone a lot, it's probably a good deal, for those who don't and simply want it for its wifi capabilities, then you can save ten dollars a month and having to sign a two year contract.