If a recruiter says they want to schedule a call to tell you the hiring decision, is it usually a good or bad decision? Why would recruiters even call to tell a candidate they were rejected?

Ok so a recruiter emailed me about a good time for her to call and tell me about the job decision. I was happy that I got the job, but I started to panic because I read plenty of recruiters also calling for bad news. During the call, she says they are moving forward with another candidate. But why would she even waste my time with a call? She could have just emailed me. Sheesh.