Most parents are aware of the need for flexibility. Glad all your kids performed as expected. Many do not. OP-imho, you have unrealistic expectations of your friend. Help her instead of judging her. Never wake a sleeping baby, especially when it's the only sleep he's getting.
My kids both performed as expected. It's all about sleep training. I believe the OP is frustrated with her friend because she just lets the kid (not even a baby anymore) fall asleep and wake up when he wants. It is annoying to parents who realize how easy it is to get babies to sleep on a schedule that other parents sit a complain about how sleep deprived and overwhelmed they are when they don't have to be. I put both of mine on a schedule from the time we came home from the hospital, they both had it down pat between 1-2 months old. I got plenty of sleep at night, I had nap times you could set you watch by literally since I always put them down and got them up at the same time everyday. This gave me plenty of time to do all my laundry/housework and chill with some ice cream and TV during naps and left me nice and refreshed to Play and snuggle during the times they were awake. Most parents aren't willing to listen to any crying in the beginning and can't see that it is for the childs well being down the road, so they create demanding little monsters by letting the baby dictate the schedule and feeding on demand and letting the sleep/wake whenever they want. I understand OPs frustration, I've felt it towards other parents as well. It's like nails on a chalkboard to me when someone says their baby won't sleep on their own. Of course they will, they are babies, they can't go anywhere. Put them in bed and they will eventually sleep. The problem is mommy can't stand to hear crying, not that the baby can't sleep. It's for the babies own good. By 8 weeks my kids both had very balanced schedules where they were well fed and got great sleep. They were happy and content! It was worth a few weeks of crying that they don't remember at all. As opposed to babies who didn't get enough sleep and were cranky and demanding and not well rested.