"NB?" Whether one has experience flying a back course or not, it's one basic type of instrument procedure, and if one has an instrument rating or ATP, one should understand it.
Nope, if you narrow that down to a US ATP you are right, outside of the US a backcourse is very rarely used if at all. In fact, my company tells us quite clearly that using back course procedures is prohibited as we do not train it. I learned how to fly as i did my training in the US, but haven't flown any kind of backcourse procedure since, and of course it was not a topic during my ATPL tests.