GitLab acquires Gitorious

I would not write off "FLOSS + network effect" yet, just because of gitorious.

You need to have a competitive product and gitorious just did not have that. The one advantage Gitorious had over github was the license, which is not enough to attract users. And without users no community, and without community no contributions.

An other show-stopper for building a community was the lack of communication. The blog worked best for me, but even there were really infrequent updates (check out blog.gitorious.org: There is not even a mention of gitlab at this time, last post being from Dec. 4th).

Without a community sharing the development burden it is no surprise that gitorious failed to keep innovating. That makes it impossible to keep up with the competition, making gitorious fall back even further.