The vast majority of home cooking in the US measures in cups. Certainly there are people in-the-know who are going to be more precise and measure by weight, and most restaurant kitchens will probably do so as well.
I agree it's not great, but ultimately I've found it doesn't really matter in practice, even for baking most of the time. For regular cooking I do get frustrated when I'm asked to include "2 cups of shredded chicken" or the like, but ultimately it really doesn't matter. Being off won't ruin the recipe, and often more or less of a particular ingredient is a matter of personal taste anyway.
I have a kitchen scale, but it's always simpler and easier to grab and use a measuring cup, so that's what I do most of the time, unless the recipe actually calls for weight without giving volume.
