I’ll make you a deal. If you are careful not to cause harm to the natural places you visit so that I may enjoy them just as much when I visit, I’ll do the same. That means no cutting switchbacks, especially on heavily used trails.
Hiking off-trail is fine where allowed and it is allowed quite often. But it does damage when done repeatedly in high traffic areas. This damage can easily lead to erosion since the trail builders didn’t build in durability features like water bars like they do on the real trail. Use common sense and walk on the trail if there is one close enough to where you want to go.
Trail builders and maintainers do us hikers a great service. Don’t ruin their work and cause trail erosion for the rest of us. Practice good etiquette and don’t cut.
Here is a good Forest Service resource if you want to understand a little more about what the trail builders are thinking and what goes into switchbacks – Trail Construction and Maintenance Notebook, p. 12