2D label leaf or or not leaf?

[eimixas]

Is there any specific reason that 2d labels are leafs?
And is this "Leafs could not have children" needed at all?

Thank you

[daniel]

It's mainly 'logical' (as a label has no sub-element / component / structure). It is also a way to optimize the code at some places (as we don't have to look for siblings, etc.).