You aren't voting against anyone. You either vote for someone or you take yourself and your vote out of the picture and ceed political control to more passionate people. That is what they are doing, "I will let the most passionate people choose our leader and I stand by their choice" not "I don't like anyone."
How can you possibly feel comfortable ascribing a motive to over a hundred million people? You didn't answer the question on why this interpretation is more valid than mine.
I'm not ascribing a motive. They might believe whatever to justify their inaction. I'm just outlining the actual effect of their choice, which is quite literally to allow for others to choose.
This is a subtle moving of the goalposts. The original point from misnome was that people who didn't vote "voted for whoever won". Your last point was that non-voters inherently "stand by their choice". Neither of those is "the actual effect of their choice". They’re attempts to interpret the intention of non-voters.