It's a matter of economics and GM is hurting . . . badly. Ford is not doing much better and saw this a few years ago. They are stopping production of all sedans except for the Mustang and a compact Focus crossover vehicle.
I also hate to see Camaro production come to an end from an enthusiasts point of view. Competition improves the breed and the Camaro vs Mustang has continued to bring us better cars through the years as they attempted to one-up each other.
The Mustang started the "Pony car" market and led the way for the Camaro, Firebird, Javalin, Barracuda, and the Challenger. All the manufacturers built and improved some really great Pony cars as they competed with each other.
The death of the Camaro will be a sad time for all Pony Car enthusiasts.