There is no "magic number" that applies to number of times brass can be reloaded.
.45 ACP can typically be reloaded up to 15-20 times if the load pressure is light. 9mm can go 10+, again depending on load pressure. Rifle brass will usually have a lower lifespan, again because of the load pressure involved coupled with the amount of resizing done.
Also, no one person will get the same result as another due to many factors. Your firearm may damage the extractor area more or less than someone else's firearm. Your resizing techniques may differ. Your perception of when brass is done for will differ from another's perception.
The statement referred to here about 6x is truly FUD