I don't think this system was meant to be perfect. It's just more resistance to bribes, coercion, and having you're values twisted by establishment political relationships.

Corporate lobbying groups would still exist, but they would be forced to make their case in the open, in front of the jury, not while kicking back some drinks or a wink and a nudge along with a campaign check. Also, not all lobbying groups are evil. To name a few, the EFF, ACLU, and FFR all have lobbying aspects their orgs. This would level the playing field between the good ones and the ones with deep corporate pockets.