Minnesota is right up there with Iowa for average counts, but aside from 2010, does anyone really care about Minnesota beyond the chasers that live there? No one sees most of those 40-50 tornadoes. The storms that they come from are barely supercellular. 1250 MLCAPE, 100 SRH, 2% days are the norm here. The only reason I'd really give IA the edge over MN is because it occasionally has some big discrete cells and the road network is much nicer than anything in MN north of I-90.
Ultimately the dynamics of the CONUS landmass favor certain types of storms in certain areas, and MN/IA suffer from this. If you go one state west from IA, the quality and quantity of tornadoes jumps quite a bit, and you get even flatter land with fewer trees/urban areas. Hell, Nebraska's offerings from this year alone dominate Iowa's from the last 6 years.
Every place in the Plains/Midwest gets tornadoes and occasionally some are beasts, but you're deluding yourself if you think that IA hasn't been way behind the curve compared to its neighbors the last few years.