The Difference Between a "B" and a "B"-Plus

Kvetch, kvetch, kvetch. Classes start in three weeks, and the bosses have mandated a revolution at the University of Texas, Austin: we can no longer give only “A,” “B,” and “C” grades, but must give +/- grades too, such as A-, B+, etc.
With 600 students this fall, I can imagine a big change in griping.
One colleague says there will be less — because with less to argue over, each argument will be less heated. I say more there will be more; with more dividing points, more students think they’re on the edge of a better grade. The first effect is a negative change at the intensive margin, the second a positive change at the extensive margin.
The issue is analogous to the effect of some incentives on hours per worker (the intensive margin) or labor-force participation (the extensive margin). It’s similar too to the breakdown of the unemployment rate into the duration of unemployment spells and their incidence (number of people unemployed this year). The burden of workplace injuries also depends on their severity and number. In these other examples, the costs to society are greater if duration or severity increases than if the number affected rises.
With grading complaints, though, better for me would be a few very unhappy people rather than lots of smaller complaints.