No, not hardly at all.
Generally there's three classes of trolls (this is just my opinion):
Griefers are what you describe. People who are more interested in gaming the implied social norms of the community in order to destroy it. These people suck, but totally blocking them eliminates the second class:
Dissenters are people who just disagree with you, and considering nearly every open source project is started by opinionated dissenters it's just bound to happen. I believe that without these people though your project dies because your ideas stagnate and you never really deal with actual criticism until it's too late. Also, they may just be the vocal part of your user base that wants something you don't.
Finally, moderators who use their moderation powers to "indirectly troll". By this I mean people who unilaterally deny people's communications because it would interfere with their hidden agendas. If you go look at nearly every failed community, at the heart is someone like this.
What I think, and what we'll find out, is that what really drives people away is not the presence of all of these, but the dominance of one of these types of "trolls". My idea is to just balance them out and give the community a real vote on what is what.