In the kitchen I rarely measure anything...
It's more a case of ratios than exact measures -
And cooking for 100 people it's more of a case of salt by the handful than a pinch...
When I start I pour out a small bowl full of salt and work from there, the same with spices out of the big jars, all by hand, it would be very time consuming to stop, wash your hands, take the spoon out, measure, pour out the spoon, wash the spoon... you get the idea.
At home I do use pinches, I only measure stuff when baking -