Okay, hindsight is always twenty-twenty, but let's look at it from what the crew was thinking. Other airlines were reporting the braking as "fair," so they ran the numbers for fair and determined they could land. The fact that it went from "fair" to "poor" between when they determined their landing numbers and when they landed is what got them in hot water. I don't know about everyone else, but I don't re-run the landing numbers every five minutes.
Here is what I think their mentality was: the passengers in the back expect to go to MDW, the connecting passengers expect to make their flight, and the passengers waiting expect this plane to be on time. The pressure is on to get that flight into MDW. Now, it's definately safer to divert somewhere else (possibly IND), but the desired outcome is a landing at MDW. So, once the braking reports improved, the pilots saw that their priority was at least possible. It's even possible that some of those crews REPORTING "fair" braking were actually getting a bit worse, but reported it as fair to keep from getting tagged by their company. Truth is, no one knows.
It's tragic that a life was lost, but crucifying the pilots for more or less following procedures is not going to bring that person back. The only thing we can do is learn from what happened and apply it down the road.