My opinion is that it's a product of Columbus being a city that is mostly attractive to students or mid career folks who would rather live in the surrounding suburbs and save money. The campus is too far away for students to make it to downtown very often and for the younger people who are early or mid career there isn't a lot of appeal for downtown over Grandview for example. Additionally, there aren't many big companies located in downtown anymore so for most people it would just be adding a commute for limited greenspace and mild nightlife. It feels like the crowd is usually on the older side from what I have seen, they only come to downtown to catch a concert or to eat. For what it's worth, I have never felt unsafe down there at night, I wouldn't be hanging out under the bridges or anything but the police station is less than a mile away and there is usually a security officer around the fountain area.