MURS is intended for private, general use rather than open, more social communications like CB. It is not as widely used by the public as other services, so emergency communications are not likely to be monitored. Also, there are only 5 channels available for MURS, so tying one up as a dedicated emergency channel greatly limits its use and is not very practical.
Although some preppers may use MURS for more private low power, off-grid communications between groups, they usually tend to stay with more widely used and accessible services such as GMRS, FRS and amateur radio.
As a service intended more for private use, MURS is a great option for groups who want keep their short range communications within their own local domain with less interference from other users outside their group. Since it can be used for personal or business use without a license, MURS can be an attractive option for certain outdoor team activities and some local shops and retailers. It is no secret that some big box stores such as Wal-Mart use MURS radios in their stores for staff communications. MURS is also used in some homes and private properties for intercoms, monitoring and audio surveillance systems, such as the Dakota Alert systems.
There is an in-depth discussion on MURS, including practical uses and its general applications in episode 11 of the Two Way Radio Show Podcast called All About MURS. It answers a lot of questions about the MURS service.