Illinois and the Chicago area in particular has a lot of old structural firms, and good noes at that. I have had occasion to work a few of them. Maybe they want to keep Illinois work in Illinois? I don't know.
But, the fact that an Illinois RA can seal structural drawings is a flat out joke. That's where the special interest is. Maybe I am uninformed but I doubt I could find a RA that could run seismic numbers and design for me.