I cannot fathom why anyone would forfeit their highest privilege in a democratic society which is the vote. But that some do is not an issue, since such behavior usually is part of fringe elements and not the mainstream of any society. There will always be such fringe elements in any society. But the Wiki you posted defined them pretty well, nonetheless:
"Donkey votes are typically cast by uninterested voters, protesting voters or voters ignorant about the voting system. As voting is compulsory in Australia, "donkey votes" are a measure of apathy and ignorance."
Sounds about right to me.
I dont think that is necessarily true in the United States. For decades, the ultra right conservatives have had enough support and represented enough of the demographic to get themselves into the White House, control Congress and the Senate and most of the Supreme Court. They represent the majority of all mega-corporate leadership in the US. They own the media. But the citizens of the US have swayed decidedly to the left, making the old "moderate" the new "right". The old right has been put to bed...permanently. The power to elect a President has been forever stripped from the far right. Whatever the case, making the vote compulsory in the United States would solve a lot of problems created by lobbyists and gerrymandering.
Perhaps all those donkey votes are the reason not enough votes are counted towards those who could change harmful national policies?
No, I still think voting in a democracy should be compulsory when one becomes voting age. I think that it could be done electronically though. I think our Electoral College should be dissolved in favor of a popular vote system. But in every scenario, I would rather the vote be compulsory.
