Why?
The way it is means you have to insert a dummy song for fast adding several songs at the end.
Internally, the operation is load song “offline”, then paste.
All text or image etc editors insert (paste) before the selected event. And yes, sometimes that’s not what you want and I understand your point of view, but if we were to insert after the selected event, how would we insert to the top?
Actually your approach of a dummy Song is not a bad one. It costs close to nothing and serves the task 
Understood.
Anyway - the natural workflow of creating a setlist is from beginning to end,
so isn´t the probability much higher for the “after” alternative - and so the usability?
When we practice new Songs, those appear first. Your mileage may vary