Why Is Mega Man Powered Up Not On The PlayStation Network?

Siliconera writes, "Mega Man Powered Up, a PSP remake of the original Mega Man, was released in 2006 by Capcom, but only as a retail title. In the years to follow, Mega Man Powered Up was never transferred to the PlayStation Network, so you could download it onto your PSP like other Mega Man games such as Mega Man Maverick Hunter X.This week, a PlayStation Vita owner asked once again if there was any chance of the game seeing a PSN release."