Given that we're so small at the moment, why should a post need an upvote to be at all visible on the default sort? It can the only post of the past two weeks, but if there's no upvote, it doesn't get seen. It's very impractical.
And even if we go with this logic, why should the criterion for a post being seen be whether OP remembers to upvote their own post? It doesn't make sense. If you think that posts should only be seen if someone opts to go through new and give it an upvote (because otherwise it's not a "hot" post), OP shouldn't be able to do that.
Right now, we have a system where a major factor in post visibility is, "Did OP remember to click the upvote button?" It's just not beneficial.