The reasons are numerous for going to 800 in NC, and the frequency range by itself isn't really the reason. It's the desire to have a unified effort toward interoperability, and somebody in the frequency allocations stage sold 'em 800 MHz for the frequency availability and trunking as the most efficient technology. They had to pick a frequency range and a technology, and based on the info at the time, what we're seeing built out is what they chose. Trouble is, the control and interconnection for a wide area zoned system is complex, and 800 MHz requires more sites due to it's propagation characteristics, which means the infrastructure is even more obese. The more complex and radical the new is compared to the status quo, the more complex and time-consuming the process will be.
I'm sure there are plenty of opinions circulating about better ways to accomplish the goals, if only because there are some very good examples of local poor planning and execution as the system build out progresses. No one person or mega-committee can foresee all the political and legislative obstacles and complexities in financing and carrying out a radical changeout of technology, protocol and infrastructure, especially one that requires local food chains to unite and form new relationships and relinquish some power.
Most of the problems in these situations come from the inadequate understanding of the technology and requisite education on its use, the inadequate financing due to lack of local, state, and federal monies, and the ever present reluctance of the old guard to pay for something they can no longer completely control.
Let's just hope that the changeover processes don't result in life dangers getting the upper hand.