Because 30 to 40 years of service means nothing to Republicans:
A few short lines in the 2015-17 Senate budget would eliminate state-paid health retirement benefits for teachers and state employees hired after January 1, 2016.
“This will negatively impact the state’s ability to recruit good, qualified folks,” said Richard Rogers, executive director of the North Carolina Retired Governmental Employees’ Association. “In the future, I don’t see folks sticking with state government for the long term or for a career.
They don't want "good, qualified folks," working for the people, because that would make it harder to tear down government agencies and institutions. Better to fill the ranks with mediocre, unqualified folks, because it will condition the populace to not be dependent on a functioning public service machine, and make it much less controversial when that machine is finally switched off for good.