I don't regard low turnout as major as an issue that you turn it out to be. The majority of Japanese people I've met just aren't very interested in how the government works, and not really interested in things changing. Honestly, aside from a few key points (childcare, social welfare, etc), I'm not really interested in rocking the boat or making major changes to the government. I vote because I think that it's my duty as a member of society, but other people just don't feel that way.