My limited understanding is that it was more complicated than that. As with everything the Navy procures, it meets the initial specs, but when the specs change (not sending certain info, in this case), the software needs to be rewritten, which of course it wasn't designed to be rewritten in the first place.
The same issue happened to both the Hornet and the H-60 with the AOP (or whatever jet guys call the system software). As capabilities were getting added, the code was getting bloated, and you couldn't rewrite the code without starting over. I lost track of where VFA went with this, but I think they went the same direction as H-60 and it's now on the top 10 (and I think at least partially funded, if not more so).