Juries need to be of “peers”, because you don’t want an all-white jury in the Old South trying a black man; or an all ghetto jury trying a white man in 2017.
The jury is there to prevent the state from forcing a wrongful conviction.
It is NOT there to “represent a cross-section of the community”.
(The community is not on trial or in danger of facing wrongful conviction.)
Juries are a funky institution, in some cases perverted by the legal system, in some cases nothing but perfunctory window dressing, and in some cases doing righteous work.
Most jurors are ill informed. Think "WalMart people," and that cohort is s step up from the typical jury. Juries are people to stupid to get out of jury duty.