Austria (aka The Hapsburgs not the Habsburg - I think that's the name of an orrrible disease!!!) was after the Tyrol and adjoining areas, the lands closer to your centre of gravity are those most naturally sought after.
The more northern lands lend themselves to be cut off in war - easily lost and hard to garrison. Lands divorced of a common border with your centre of gravity are a liability, cannot be garrisoned with peace time forces, but have to have an Independant Command from the Army, and as such are less desirable.
Consider Vienna as the focal point, then imagine ever increasing circles from that focal point - the lands thus encircled are those best sought after by the Hapsburg Emperors.
Bohemia, the Tyrol, North Italy (and Venice) and the Balkans all suddenly seem of vital importance. Now consider Hungary - close enough to be Very Important; independant enough to be a massive problem.
The Austrian Netherlands at this stage were nothing but a liability to the Hapsburgs.