Because sales taxes are not based on the ability to pay. Sales taxes are essentially underhanded. One sees different brands of coffee on the shelf, ranging in price from (very) high to (possibly) affordable. But that's not the price of the coffee, 'cause at the cash register the agents of the state are going to tack on 6 percent or 10 percent or whatever percent, and you've been snookered. Worse, sales taxes are regressive, meaning that as income decreases, tax as a percentage of income increases.
And the Democratic grandees in the state Senate intend for us to pay more of this regressive tax, while they coddle their corporate buddies. N.C. House leaders had wanted, for their part, to reform corporate taxes by instituting "combined reporting," which would have made it harder for mega-corps to hide their profits, which is to say, pay their fair share of state taxes for the privileges of doing business in N.C. But under pressure from the state Senate, the House has abandoned that reform.
A 1-cent sales tax increase (which seems likely) would raise $843 million in the next fiscal year. Legislative analysts predicted requiring combined corporate reporting would have raised $18.5 million this year and $43 million next year. Apparently, our working citizens are much greater money-bags (and softer targets) than big corporations
You don't have a lobbyist down in Raleigh, most likely. The corporations do.