Because the Austrian national anthem is sung very slowly, it completely destroys the singing of it.
That's why I oppose the change that is proposed. I would support the change if it rhymes and doesn't destroy the singing.
Imagine the US anthem is changed from "The bombs bursting in air" to "The bombs bursting in air and over in Iraq, Afghanistan and Libya" - would you still like to sing it ?
That would be pretty awesome, actually. Besides, it's not like some awful celebrity isn't just going to ruin it anyway.