Gosh, quite a range of opinions, but will definitely work towards him having a key attached in his bag.
Also it seems by your post that your DH is anxious and passing that anxiety on to ds. @Noshadelamp
Yes, during our family discussion about it, DH made it clear that if a key is lost, the lock must be replaced that same day in case whoever found it followed DS home, which I think added to DS's worries.
Other thoughts... As for installing a keysafe myself, I think DH's problem is that he's not sure he is okay with having one, not just that he isn't getting around to it. So, if I install it, and then he decides he doesn't agree with using it, it's no help.
We're not in either a terribly crime-ridden area or a terribly nice one. I wouldn't worry about robbers nicking my laundry from the line, but it's been heard of for video doorbells to catch people to trying car and house doors in the night.
We're medium-back from a medium-busy road in a London suburb. At the time of day in question, though, it's a very busy road, because we're across from a primary school.
I work from a room downstairs where I can see the front path, but it's through a window to my side, so I don't have a perfect, constant view. Our gate is very squeaky, though, so I can hear it from where I work.
I'm generally okay to excuse myself to answer the door in an average hour-long weekly meeting. But it's awkward for this one, as it's our daily status meeting. It's only 10-15 minutes long and is every day. It gives the impression that I can't be trusted to work for even 10 minutes when every day during it, I need to step away.
Where and when I grew up, our house didn't even have a lock on its door. 