Just guessing , they don't want anyone else to have it.
In my opinion, it would be more accurate to say they don't want RailAmerica to have it. CIND (RA) holds right of first refusal on this line (as well as the line to Frankfort) should Conrail or it's successors (CSX in this case) decide to sell or abandon the line. This dates back to the Shelbyville Secondary sales agreement between Conrail and Central. My guess, again, just speculation on my part, is that if this agreement did not exist, CSXT would have already found a way to quietly spin this line (and maybe even the Frankfort line) off to their little stock investment known as the INRD with an agreement to have INRD to the physical switch and CSXT to keep the lion's share of roadhaul revenue.
Reason this piece was not sold to CIND in the first place was at time of sale, Gencor Automotive (or whatever their name was) was kicking out a dozen or more 86' autoparts boxes as day going to General Motors in Wilmington DE and Framingham MA. They where not comfortable turning the originating switch for this high dollar traffic over to a shortline. By the time Gencor lost the GM contract, thus drying up and blowing away, CR was already in the early stages of their break up and where not interested in entertaining selling ANYTHING.