YADA doesn't abstract any underlying system, it abstracts access to the underlying system. You can think of it as a pluggable web service that you slap on, say, a legacy warehouse, except it can also reach into any other system, enabling access to data using the same standard syntax.
It's like a BI or ETL tool in that respect, except those tools wall off the work you've done and limit repurposing. BI tools generate reports and that's pretty much it. You couldn't, for example, point Spotfire to Cognos, you'd connect them both to the db instead, distributing the credentials, and possibly construct the same query in both places using their interfaces. With YADA, you could instead write the SQL once, and get the data from anywhere.
I do agree with your sentiment however, that as innovators we always think there is a better way, or more commonly, that their _must_ be a better way, because we don't understand the problem fully, or grasp the complexity of the current solution. Often we discover we're not the first to think of a great idea. I'm sure there are similar tools to YADA, but I also think YADA has potential to offer a wide array of users some options and combinations of features that are distinct in the marketplace.