Cuz he's a military man, and many of them tends to held a strict discipline at home as well, especially with their children. It's quite the usual trope in that environment honestly, but regardless he seems like a dick for another reasons.
Caution: Many people won't know what the definition of "trope" is, especially when you follow it up with comparing it to someone "like a dick" in the same sentence.
In your example, it's BS. Stereotyping. I spent 27 years in the military and never forced my kids to call me "Sir".
I was the one in the military and using "Sir" was part of
MY job requirement for
MY professional WORKING environment. My CHILDREN weren't...and shouldn't have been...forced to be a "little soldier" as part of their growing up. And most...if not ALL...of my military friends with children never forced their children to "play soldier" either.
Most professional psychologists would consider a professional military parent forcing his children to call HIM "Sir" an indication of a self-egotistical parent on an immature power trip. It might be OK to teach them to use the term "Sir" when engaging with other older males outside the family, but to force the child to call the child's PARENT "Sir" or "Ma'am" is way overboard. The vast majority of most military parents DON'T do it.
