This is and can only be decided by the parents. Every family has different demands and ways of doing things.
When I was pregnant with my first son I read everything I could on kids and babies! Yes I was one of those moms to be! In my readings everything said if you want a good sleeper you need to keep a good sleep schedule. I love my sleep, so having good sleepers was one of the things of top importance for me! With a sleep schedule comes the rest of the schedule.
It is very hard to stick to a schedule and revolve everything around that schedule. For me, it was very important to stick to the schedule for the first 2 years of my oldest son's life.
There were different reasons for this including my son being in daycare and us working outside of the home. Then I started an at home daycare which I had other kids on the same schedule. It became such an easy routine for us and worked very well.
Sometimes I would make exceptions, but they have been few and far between. Now that I have the new baby, I have stuck as much as possible to a schedule. My oldest son still takes a nap most of the time, and I time everything else so that they are in bed at the same time. Both boys sleep through the night pretty much every night and are normally ready for sleep at bedtime.
I have gotten remarks and judgements from different people about being less strict and schedules not mattering or making a difference. These people may not have done it the same way or may not be doing it the same way, and that is their choice. When people tell me that I should stretch their schedules or make exceptions more often, I smile and tell them that this works for us and that having a schedule keeps me sane and my household running well. If they want to deal with the kids throughout the night and the next day when I veer too much from the schedule, they are more than welcome to stay the night and deal with that!
If you are considering not putting your kids on a schedule because of what other people think you should do, don't let them make that decision for you. Only you know and your significant other knows what is best for you and your family.
I made this decision and it has worked extremely well for the boys and that is who it is about, not me or my availability to be able to do things when they should be sleeping.
Good luck on your sleep schedule, or your not sleep schedule!