His point is that the engineers wanting to opt for "not intern" isn't really a data point on whether interns are helpful. It may instead be a data point on the propensity for people to opt out of work when they have a good excuse.
Wouldn't it go the other way? Instead of working, you're "mentoring the intern" over a long lunch and telling them long meandering stories about company lore.
Wouldn't it go the other way? Instead of working, you're "mentoring the intern" over a long lunch and telling them long meandering stories about company lore.