Compulsory voting
Compulsory voting is increasingly resented by citizens in some countries such as Brazil, the largest country where compulsory voting is enforced: at the last presidential election in 2014, some 30 million voters, about 21% of registered voters, did not vote, despite the fact that Brazil has some of the most severe penalties enforced against non voters.
Donkey vote
In systems where voting is not compulsory, it seems counter-intuitive that many who attend the polls would be apathetic. However, there may be countervailing factors that produce a "donkey vote" even with voluntary turnout. In many US elections, a voter may well be intensely interested in (e.g.) the Presidential contest but not in other, less prominent races on the same "long ballot".