Does Linux Lack a Killer App?

I don't know that Linux "lacks a killer app" but I will say it is a mystery that, after all these years, a free operating system can't gain more ground on one that costs hundreds of dollars.
What Linux needs most is games, said Hyperlogos blogger Martin Espinoza. However, "if you were trying to narrow it down to one app, it would probably still be Photoshop. For all the talk of how great GIMP has become, usability is still an abject nightmare, and in spite of the OSS community's self-back-patting regarding documentation, there is no documentation for GIMP which is not pathetic."