Two excellent content replies offered by 20633mom and cactus hat.

Shearing plants into hedges requires less work and knowledge than selective hand pruning. Shearing will likely be performed with a gas or electric hedge trimmer with greater likelihood of damaging improper cuts, often ripped branches instead of clean cuts. Overwhelmingly, shearing with a hedge trimmer by a lawn maintenance crew or "landscapers" involves using an unsterilized piece of equipment. Shearing is the faster way to make a buck leaving behind the destruction for unsuspecting clients that assumes they got a "good deal."

Worse to suggest shearing into a hedge ignores that not all have or desire an overly formalized desert landscape. Free form desert landscaping designs are less environmentally destructive, organic and representative of Nature. Worse again is ignoring knowledgeable hand pruning is what makes a stronger more structurally sound healthier Texas Ranger than shearing.

Expect experiencing multiple levels of marginally or unskilled ignorance and results should you agree to their proposal.