> Democracy as implemented is stupid.
> I want to vote on policy I care about and understand, not a person I've never met who I can't necessarily trust that's meant to represent me.
Representative democracy is designed as a compromise between giving power to the people and giving (what's perceived as) too much power to the people.
In the case of a true direct democracy, many fear the ignorance and apathy of the average voter, and wonder if the majority rule would lead to tribalism and repression of minorities. That said, the few actual examples of direct democracy don't really seem to have borne these fears out.
In a way it comes down to how much (or little) confidence you have in your fellow citizen; "the best argument against democracy is a five-minute conversation with the average voter," and all that. I veer towards misanthropy, so from that perspective direct democracy doesn't do a lot for me... seems like there's no perfect system.