I doubt that's how the German Hapsburgs saw it.
The normal procedure was for the son to inherit all his father's possessions. Which would have meant Charles V handing over his German lands as well as Spanish lands to Felipe.
However, in this case Charles' brother managed to abscond with half the loot. Half a loaf being a great deal better than none.
So it would be more accurate to say the Spanish branch was unfairly deprived of their German rights than the other way around.
A minor technicality at the time, I am sure but just another reason the Hapsburg’s got a bad rep for being elementally stupid. Spain’s possessions were worth a war ~ if only for access to the vast silver resources that turned the Spanish trade dollar into a world currency ~ which, btw, is supposed to still be acceptable in the US as $1.00