Right, your legal peers are members of the same social class (commoner, aristocracy, royalty), not people who work in the same field. In the US there is only one official social class, so everyone is your peer.
There does seem to be an issue with baseline education standards and the ability of the jury to understand the evidence which they deliberate on, however. To an extent it's the lawyers' job to ensure that the jury understands their arguments, but no reasonable effort from a lawyer over the course of a single trial is going to make up for a lack of basic familiarity with the subject matter, which might normally take years to acquire. There is something to be said for systems which rely on professional jurors rather than random members of the public.
I once asked a friend who litigates patent infringement cases how a jury could possibly come to an informed decision on these cases. He said that it is definitely a challenge but that juries are pretty good at discerning when someone is lying or dissembling and litigators can build cases or defenses around that.
Definitely anecdote and not data, but I found it interesting coming from a litigator in this area.
There does seem to be an issue with baseline education standards and the ability of the jury to understand the evidence which they deliberate on, however. To an extent it's the lawyers' job to ensure that the jury understands their arguments, but no reasonable effort from a lawyer over the course of a single trial is going to make up for a lack of basic familiarity with the subject matter, which might normally take years to acquire. There is something to be said for systems which rely on professional jurors rather than random members of the public.