I reviewed answers on 2015 moderator election questions and noticed that only 6 candidates sent answers. I was curious for other candidate answers, @AmitBera @benmarks @Flyingmana @SanderMangel did you forget about them?
From a purely technical standpoint, yes, the Q&A is optional for mod election candidates. The system doesn't know or care about whether any given candidate provided answers or what the community thought.
Individual voters, however, are welcome to decide that not participating in the Q&A is a huge red flag, or that participating is irrelevant, or anything in between.