No, I'm not saying that. In practice, AFAIK no spambot has ever acquired more than 2 rep. Spam is flagged really fast, and it's also downvoted at an astonishing rate. I imagine it would be possible for a spambot to thwart the system, but it would be pretty hard, actually. It would require a much greater degree of agility and coordination than spambots tend to have.

For perspective, it would be far easier to spam the front page of Hacker News, and yet most people agree that HN's system works pretty well.