It is not always performance that is the main consideration. If you are developing a library and so do not have control of how threads might be used with it the

It is not always performance that is the main consideration. If you are developing a library and so do not have control of how threads might be used with it then it may be vital to ensure a lock can never be held by a thread which could be suspended. I agree though that the use should normally be contained to a small area and the details carefully abstracted away from the rest of the code because it takes real care to get the details right.