a couple of years ago duncan kibet was not an invited runner to the san jose marathon so he paid his own way and entry fee and won the race.
also a couple of years ago asmae leghoui (i am unsure of names spelling) was not getting in as an invited runner at any race because she was a convicted drug cheat coming off a ban, and she won most of her races, but eliteracing diector the late mike long told her she was not welcome in the races he put on, but she entered with the masses, so long literally pulled her off the course and tried to give her entry money back.
these are 2 different cases from chicago, but it shows in the case of korir and kibet that sometimes you get an good runner in the field who can upset the way things are supposed to go.
and in leghoui's case drug cheats do not have to be allowed in races even after the ban is over.
if chicago had just stayed with the plan for a mass start there would be no controversy and mass starts give unkowns the possibilty of making a name for them selves. i also think that even if you are not an invited runner you should be allowed in any race open to the public.