re: Why do new managers always come in and want to change everything?

It really depends on the reason they were hired. I've been hired before to fix a laboratory. It was in shambles with 4 major lawsuits against the blood bank. I spent a year rewriting procedure manuals and instituting valid quality control and decreasing a terrible staff by a third. Raised the lab from a solid F to maybe a C. But the administration couldn't believe hardly anyone in the lab "liked" me. (they now had to work and work right with 33% less fewer people) Within a year I had to leave because two thirds of the crew "didn't like me". Of course, I figured they planned they entire thing. They hired a old guy to just sit in the office, I had done the hard part. But, thats life.