Personally, I appreciate this gesture, but there is a fundamental functional component missing from the equation: An arch was born from stone masonry rising from a column and arching to meet an adjacent arching column, meeting at the keystone in the center of the arch. Such a form was born naturally out of the attributes of the material. The great architect Louis Kahn (who designed the Salk Institute in La Jolla, San Diego, among many other works) said: A brick wants to be an arch.
There is, therefore, a particular beauty in such a built expression. In contrast, the newly-built representations of the spanish style by current builders form the arch not by the merits of the material, but rather via a copy-cat appearance using stud framing and plywood. The merits of wood frame construction shine through in the post-and-beam style of architecture, since members are straight and have good compression qualities in the column (post) and both compression and tension qualities in the beam - where the top half of the beam is in compression and the bottom half is in tension, due to the flexion of the member. So when I drive by a new development and see arches formed out of plywood, I regard it somewhat apathetically.
Unfortunately, since California is in Zone 4 for earthquakes (highest hazard), masonry arches can be regarded as unsafe. Typically we see masonry, such as concrete block, forming rectilinear openings since the open cells within the material are filled with rebar to provide resistance to destruction due to earth movement. Regardless, the Spanish style is here to stay, as a memorial to California history, and will always be built using today's construction methods, even if there's a touch of deception in the bones of the finished product.