THe Super Hornet is optimised for Carrier-based operation. The US is the major market for carrier-launched fighters; I wouldn't expect a huge export market for the Super Hornet. The F-16 is a much more cost-efficient platform for any buyer who will launch from land only.
So was the Hornet-but it won orders from around 6 countries!!! Being carrier-specific is in fact an advantage for some countries which need aircraft with rugged engines & reinforced undercarriages among other things.