[zestyping]

There are some situations where a transition is warranted; they're fairly special and rare situations, but I agree with you when you're talking about "random stuff opening and closing".

In broad terms, if the user cannot predict where things are going to move (typically because the position itself reveals new information, such as the data points in a data visualization), then a transition animation is warranted. On the other hand, if the UI responds to a user command by doing exactly what the user expected (such as expanding the children in an outline list when you click to expand), there is no need for a transition.