*sigh*
I for one think it's pretty obvious that setting up an international business overnight would be extremely complicated, therefore costly and more likely to fail than starting in one location, tweaking it to get it right, and then expand to other countries.
Don't forget that in this case, B&N has to collect payments from international customers
and pay the self-publishing author. I would assume that both aspects involve all kinds of reporting requirements, VAT and income taxes and so forth. Simplifying distribution does not magically make every single regional law, tax obligation or other requirement disappear into thin air.
I don't think it will be impossible or that they will never do it, only that it takes time.
Of course, since we live in the Intarnet age, people have about as much patience as a fruit fly on crack.
More irrational whining in 3, 2, 1....