It doesn't always happen on purpose. In fact I think more often than not it's by accident. Because therapy is so different from other relationships, so clients don't know how to navigate it. Like when I had a T, I once asked him about his kids but he said he can't mention his personal life. It was so weird for me and I felt both angry and embarrassed. It felt like such a natural question. Nowhere else would anybody not answer that question. Heck, many people volunteer that kind of info. But I quickly realized this was not a social occasion. He was not my friend. He was getting paid to help me get better and feel less anxious and depressed. That's all. But that's something I had to learn. I still did not like it, but eventually I stopped taking these things personally.