It makes sense to have the code stewarded outside of SourceForge, because it ensures that the development is completely open. We (SourceForge) value our projects' ability to own their own data, even if that means that they can move it somewhere else. By having Allura completely open, and even developed outside of SourceForge itself, we ensure that this right - the right to pack up and move - is 100% protected.
It also provides us access to innovation and ideas from outside of our own small organization, which, in turn, further benefits our projects.
Don't tell my corporate overlords, but I consider the health of these Open Source projects to be my highest goal when I go to work in the morning. I firmly believe that if those projects are more successful, then the company will be more successful. But it's the former, not the latter, that gets me to work every morning.
Taking Allura to the Apache Incubator is for the benefit of our projects. It gives us the opportunity to focus more sharply on the things that will make their developer experience better. And folks who haven't seen the new SourceForge, and are making their judgements based on old-style SourceForge projects that haven't upgraded, are selling everyone short.