"Not that much point having a tracing tool if an inexperienced admin cannot safely use it on a live system which has a problem. "
Right. Because everyone knows the best place to develop, debug, and profile code is on a production machine, and the person doing the development should be a system administrator, preferably with minimal experience.
I would say many people do know that the best place to understand the performance of a system in production is in production. If the vendors support techs can give an admin commands to run and know that a typo here or there will not result in a panic then that is a very useful feature.
A problem already solved with DTrace on Solaris http://docs.sun.com/app/docs/doc/817-6223