I will no longer be able to simply stay up at the upper landing to the staircase, if I suspect an intrusion.
Sure you will. You may not like doing it, but it's still an option.
Just like the father could have stayed inside and told the neighbor/relative to call the police.
It's true that people sometimes do things that are tactically unwise because they feel obligated to do so, but that doesn't eliminate the tactically sound option, it just makes it less attractive to them in the short term