Competition is usually a good thing, unless of course the competition is using your service to promote itself. At least that seems to be Valve's reaction to desktop app itch.io placing itself in the Steam Greenlight program and getting a fairly favorable response. 

Itch.io founder Leaf Corcoran announced on Twitter (via Kotaku) that he had been notified by Valve that the app had been removed. "the @itchio app greenlight is no longer available :( I guess @steam_games is not ready for platform inception," he said. Without directly saying it didn't want competition in Greenlight, Valve said that the itch.io app did not fall into the specific categories of software that the Greenlight program wanted to focus on. "Right now we need to focus on a smaller scope until we have better tools and processes in place," Valve rep Alden told Corcoran in a comment on the Steam Workshop page.

Corcoran also tweeted that  the app did last 12 days and managed to get as high as #4 in the rankings. 

Itch.io was launched in 2013 as a "a marketplace for hosting indie games with a ‘pay what you want’ pricing model." The company has more than 28,000 games on its service. And they don't seem to take themselves to seriously either. If you don't know about the service, you can learn about it while meditating at the same time: