Earlier quoted context omitted.
Really depends on the kid's age. Younger kids (less than 10yrs) are not able to grasp the concept of money or earning money, so explaining that dad is out making money for a roof over their head and putting food on the table is not going to cut it. At that age, they just want close interaction with their dad.
I'm happy to be proven wrong and of course this is only anecdotally but I was watching sci-fi movies at age 10 and I could grasp, at least on the surface, the underlying technology and it's purpose. When we say "kids dont understand money" I'm thinking they should start to get it at about 7 and certainly have a basic grasp by 10.
If they are raised to believe that work is necessary and the spouse who is with them while the working spouse is away doesn't whine, complain or fight with them about it then they will learn that it is something necessary. And guess what? If they don't that's to bad. You do what you think is in the best interest of your children long term not short term because you won't be around. In no way are they going to understand why you can't be at the ball game or the school play but later if you are out of work and/or you can't pay for their college that they will understand and they won't say "oh that's ok at least you came and saw me make that basket".