This is a really bad way to view things.
I've had people tell me the same thing about why they pay for certain services. Say I make $50/hour. I can paint my own room or pay someone $15/hour to do it. (we'll assume supplies are a fixed price either way, so the only difference is the hourly rate). Let's say it takes 4 hours. Some would say that paying someone $60 to do the job make sense, because in that time I could earn $200, putting me $140 ahead. But that's not necessarily the case. For me to earn that $200, I actually have to be working, not painting my room. So paying someone to do it actually puts me $60 behind.
Same thing for anyone. If he's sitting at the table reading the paper while the coffee brews, he's not reducing his earnings. If he's paying someone to do it for him, he's still not earning anything, and he's paying out of pocket more than it would cost him to do it himself.