Thanks for your interest in this!
Establishing a definitive database is what we're trying to do, isn't it? That's why we mark profiles as Historically Significant, which marks them as the final profiles for those people. It's not yet "definitive", but it is "locked". Also, I'm not familiar with those databases, but a quick glance suggests that they're based on community trees. If that's right, then they could easily contain errors, and so wouldn't be any better than our current system. Or am I missing something there?
As for the second step, the rigorous search, that is what the group is working on. Sadly, there are few of us, and as you say, a lot of duplicates! So all we can do is keep working on it, and keep trying to get more people to join in the effort.
I'd be interested in hearing more of your thoughts on this! :)