The Beginning- Przewalski's Horse

For hundreds of years the land was roamed and owned by the horse. There are still wild horses roaming free today but are not nearly as much as there used to be. Today we know them as Mustangs, but the earliest known wild horses went by the names of the Tarpan and the Przewalski's Horse.
After being discovered in the 15th century by Russsian colonel, explorer, and naturalist, Nikolai Przevalsky in 1881 in Asia, the Przewalski's Horse roamed the land until the 20th century. In 1967, the last herd was spotted and in 1969, the last individual. After failed location expeditions, the Przewalski's Horse was pronounced extinct in the wild with only two captive populations in Munich and Prague. Only 12 indivudauls of this breed remained in the world by the late 1950's.  In 1977, the Foundation for the Preservation and Protection of the Przewalski's Horse was founded in Rotterdam, the Netherlands, by Jan and Inge Bouman in order to bring back this species. Since then, the status of the Przewalski's Horse has gone from "extinct in the wild", to "critically endangered", and finally to, "endangered".
Although such efforts have been introduced, the Przewalski's Horse is still considered endangered today. For this reason I would like to ask why this is so. Does it have to do anything with the domestication of the wild horse? How was domestication sparked and why?

Marin, Lucian, E. (2011, December 14). Neigh: Journal retracts brief endangered horse paper for mysterious reasons. Retrieved from http://retractionwatch.wordpress.com/2011/12/14/neigh-journal-retracts-brief-endangered-horse-paper-for-mysterious-reasons/