Having never been through Cork, I can't comment whether it's a "nightmare" or not, but it is not a viable option for me to use as I would have to go to Limerick first.
While I admit I'm biased I think Cork airport is far from a nightmare. It has the only 21st century airport terminal, and although some people think its soulless and theres only 1 airbridge, it is modern, clean and easy to use. Perhaps the person who said Cork was a nightmare hasn't travelled there since the new terminal opened last year. Admittedly its not a great location for travellers from the West as its on the southern side of the city but Cork does have an ring road (although not a full ring yet as construction has yet to start on the Western section) so provided you're not travelling during rush hour you shouldn't have a problem. Why don't people try Cork even just once and they'll see how much more convenient it is than Dublin.