Greetings David. I should have replied to you (and Alina) a long time ago. My apologies.
You make an excellent point David, and I would venture to say that most of us agree with you--i.e., that our priority should be to develop integration with other open-source rather than proprietary tools.
However, there is a clear reason why we are developing a full integration between Arches and esri–namely, the development has been financed. The effort is driven by Historic England because they use esri products widely, and they have kindly funded a significant piece of the development. (The remainder is financed by Farallon Geographics and us, the Getty Conservation Institute.)
Our sincere hope in completing this work is, exactly as you suggest, that once the development patterns are established the work to integrate Arches with QGIS will be greatly facilitated...hopefully by someone very soon!
Thanks for your candor, I really appreciate your feedback and hope that you continue to make your voice heard for the benefit of the community.
Best,
Alison