The object, purposes, and activities of a cemetery shall be restricted to those acts only that are necessary to enable it to accomplish the purposes for which it is created. It shall not be conducted for the purpose of private gain either directly or indirectly to any of the members of the agencies engaged in such business. Lawfully organized cemeteries may be conducted and operated by those agencies now engaged in their conduct and operation, by churches, by religious and ecclesiastical societies, by cemetery associations incorporated as hereinafter provided, and by no others. However, this chapter is not intended to apply to any agency organized, existing, and operating the business of a cemetery prior to June 1, 1933, under any existing law, nor to affect any vested rights acquired thereunder. Insofar, however, as the provisions of this chapter do not violate any vested rights, so acquired, it shall apply to all such agencies.