Other sims boo my main sim, even though she's not evil

I'm guessing that your Sim has a trait that the hecklers don't like. I started up a new Sim last night and sent her to the theater to (hopefully) meet some of the townies. No sooner did she get her feet onto the pavement than she autonomously decided to go heckle someone, which was really surprising because she had been in town for less than 12 Sim-hours and only knew three Sims at the time (the University Mascot and the across-the-street neighbors), none of whom were on the theater lot.