My post was in no way to imply that anyone's org operates that way. That is why I said my disclaimer first.
One of my implied points though was that there are things that you may be willing to do at 19 - 20 that you would
never do at 30 - 35. Hence, the perceived difference between joining undergrad vs. grad.
We all remember the silly and fun things that we did when we were young and tend to look back on those events fondly. Well, I do anyway.
Joining undergrad can be part of that youthful exuberance.