One doesn't have to oppose democracy to advise folks not to vote. Jason Brennan makes a lot of pro-democracy, pro-civic engagement arguments along these lines. Here's the abstract to his paper "Polluting the polls"

Just because one has the right to vote does not mean just any vote is right. Citizens should not vote badly.  This duty to avoid voting badly is grounded in a general duty not to engage in collectively harmful activities when the personal cost of restraint is low.  Good governance is a public good. Bad governance is a public bad.  We should not be contributing to public bads when the benefit to ourselves is low.  Many democratic theorists agree that we shouldn’t vote badly, but that’s because they think we should vote well.  This demands too much of citizens.