We can think of five good reasons :

1. Hygiene
2. Non-allergenic
3. Water resistant
4. Consistent style
5. Hard wearing

Steps:

1. Use a flat trowel to apply plaster base coat over the exposed wood lath.
2. Let the base coat dry, then brush on some liquid bonding agent.
3. Apply adhesive-backed mesh tape around the perimeter of the patch.
4. Use a 6-inch drywall knife to spread a thin layer of veneer plaster over the patch.
5. Allow the veneer plaster to cure, then spread joint compound over the area. Once the repair dries, sand lightly and apply a second layer of joint compound.
6. When the second compound coat is hard, sand the area smooth with 220-grit abrasive paper.
7. Complete the repair by applying one coat of oil-based primer, followed by two paint topcoats.

Variations in water-to-plaster ratio will affect cast absorption, strength, and performance. A check on the ratio can be made at any time by weighing the slurry in a container of known volume. For example, at a consistency of 70cc (70 parts water per 100 parts plaster), wet-weight of a gypsum slurry will be about 1,674 grams per liter. This is the theoretical weight and some variation may exist because of air entrainment. The best method of determining desired wet-weight is to mix a carefully weighed batch at the required consistency. Immediately after mixing, a known volume of this batch should be weighed to determine wet-weight of the slurry at the desired consistency. Subsequent mixes should closely duplicate
wet-weight of the original batch.