I think this will become a continuation and heated debate started at https://discuss.tryton.org/t/add-in-heptapod-a-location-to-push-the-nonofficial-module/
First I think that such a place can help small developers and freelances with their source code management. Having everything already laid out and test infrastructure available can also make it more visible.
Second, personally I think that many (if not all) service providers and the bigger developers already have their infrastructure set up and are not going to move to something else. Maybe they would if the place was set up and supported by the Tryton Foundation. But even then, some use Git others use SVN or Mercurial and moving between then will change the (internal) workflow which can be a real pain.
Third, as @dalers pointed out, the name is wrong. I would call it something like tryton.sandbox just to show people that the site is a sandbox where you can play and do things without interrupting the rest of the Tryton Community. The Tryton developers can look over the shoulder and maybe ask for a module to be included in the core.
Fourth, the site seems to be focusing on the German part of the community. Maybe I’m wrong, but then enforce the English language to be used for everything including code, documentation and (code)comments.
In the end, I’m in favor of Add in Heptapod a location to push the nonofficial module - #72 by ced and have some scripts or infrastructure available that makes it easy to send your modules to the package site.