You kind of have to think of it as if you were going out to dinner with a large group of friends and you're all trying to decide on a place. A few of your group just says that they're "fine with whatever the rest of y'all pick."
Choosing a government that can influence significantly the lives of everyone is somewhat more consequential than choosing where you want to have dinner. People should be more engaged, and not just let "the crowd" decide who governs.
Would you really blame them when you end up at some restaurant that kind of sucks, or blame the majority who actually chose to go to the lousy restaurant in the first place?
I would blame them both. One group couldn't be assed to influence the result, and the other made a bad choice.