I must say, of all the things dash has done or plans to do, this user namespace thing is the most concerning to me. If Core goes with a generic and isolated solution, I will look to further diversify my portfolio. Honestly, to me, it's that significant. The way I see it, dash has just three viable options:
1. Copy and refine a better DNS; solving the problems of DNS hijacking and ISP blocking.
Users don't want yet another username landrush, or to squabble with Core over squatting and copyright. If users want to pay others by username, they can just use Peerplays or similar. In short, there's simply no point re-inventing the wheel if we're not going to improve upon it.