I think people are successful with a wide range of teaching styles, so it may be that a very personal approach works for others. For me, I want to be personable but in no way personal. I want to be professional and approachable, but my personal life, concerns, relationships, whatever, are none of their business.
My general philosophy behind this is I do students no favors whatsoever by befriending them. They have friends, as do I. They need me to teach them, guide them, give them meaningful feedback, and model how academic research and teaching can be done. I think this is especially true for women - that we serve as defacto role models, and a little professional distance in the classroom helps.
Sometimes during office hours a student will ask me something personal (usually about balancing grad school/work and family) and I will answer specific questions. But with care. My point is to tell them things that will help *them* not just give me a chance to tell about myself. For example, I would tell grad students, if they asked me, what my advisor told me - you can always stop a grad school clock but not a tenure one, so if you're considering babies have them now or plan to wait until after tenure. But I wouldn't offer up the specifics of my own family life or other personal details.