I've never been too bothered, as a user, when one product "borrows" a great feature from another, especially if they manage to deliver a better experience. I've had high hopes for Diaspora. Gave them cash when they were on Kickstarter. Tried hosting my own Diaspora server. Waited for the devs and the community to do something with the $200,000 they raised. Certainly a lot of hackers have done much more with much less…
At the risk of repeating myself, the Diaspora team had a great opportunity to do something more than put out rails code. With that money, they could have done the hard work of coordinating real world meetings with various existing projects to hash out federation issues, schema differences, etc., and been able to get dozens of indie social networks to agree on a common standard.
Yes, it's a pipe dream, but there are already dozens of decent SN platforms out there - we didn't need one more, we needed a way to make them all talk and exchange appropriate data. The big thing holding back many of them seems to be time/effort to coordinate the cooperation. There may be some NIH in there too, but Diaspora was just more one contribution to the NIH pile.
Much thought/work had already gone in to the problem space - using the $200k to help unite that previous work would have been far more productive than another Rails app.