The reason is similar to why people build emulators for old game systems: To be able preserve history.
There's a lot of Flash games and applications out there that would be completely inaccessible to people were it not for the Flash player.
For example, the Homestar Runner site is built entirely on Flash, and while movie rips of this exist, there's small, subtle interactive elements only possible in the Flash version. http://www.homestarrunner.com/
When Flash is dead a large part of the web goes dark, and that's a tragedy.
There's a lot of Flash games and applications out there that would be completely inaccessible to people were it not for the Flash player.
For example, the Homestar Runner site is built entirely on Flash, and while movie rips of this exist, there's small, subtle interactive elements only possible in the Flash version. http://www.homestarrunner.com/
When Flash is dead a large part of the web goes dark, and that's a tragedy.