A statue isn't an investment these days unless it drives tourism. Statues of Confederate soldiers put up 70 years at the end of the Civil War were good investments at the time, because placing far cheaper signage displaying direct messages to black people from the local authorities would be seen as distasteful or possibly illegal (depending on the phrasing of the message.) A sudden unexplained affection for Nathan Bedford Forrest was a clear message, and cheap to maintain after an initial outlay.