Hi Matthew,
Thanks for your views specific to this topic 
This discussion aimed at people who want to see themselves at top notch in an org. By top I mean Director,CEO etc...
Yes there might be many other factors as you said :
a) Go the right school
b) Marry into the right family
But how much factor does tenure in an org play? was the aim of this discussion as I asked below:
What gets you to top positions in an organization?? Apart from dedication, hardwork etc etc is no of year's in a company an important factor?
Raghav