Louisville is not the safest city in the country, but neither are Vegas, Anaheim, Dallas, Orlando, Houston, or New Orleans (the other cities that have hosted in recent years) They stopped doing Miami 20 years ago after some attendees got robbed.
It is a pain for me heading west. I have two options for flights, both are crappy times, long layovers in Chicago or Atlanta, and expensive. However... I'm also looking forward to seeing a part of the country I've never spent any time in.
I travel Orlando, Vegas, LA, Dallas and Houston a few times a year each, so a change of scenery is welcomed.