I always found there was one big objection to either letting the baby set me a routine or setting a very strict routine for the baby. And that was the objection known as the Rest of the World. The fact that after the first few hectic baby-focussed weeks, the world turned out still to be there and needing attention.
I had an early warning that this might happen when granddad had a heartattack in our living room just after we'd brought dd home from the hospital. But most of the intrusions of the R of the W were a lot happier than this.
I found I needed to travel on public transport to meet basic everyday needs- and buses don't necessarily leave when you need to get home for baby's nap time (dcs soon learnt to nap in the pram).
When ds was newborn, I needed to take the dd to playschool, toddler group etc; and his routine had to fit around this.
I myself found I felt a need to get out. Not owning a car makes it more difficult to always be home for dc's teatime. I have always found them very flexible, hapy to eat on the go or even to stay hungry for a little while. In fact, after the first month or two, we were travelling quite a bit and staying with other people. Wouldn't have missed it for the world.
Also, all the family my dcs have are either abroad or at a distance in this country, so that again means travelling. Of course, a child is going to be more tired when they've been sat on a train or in an airport the whole day, but that seems a strange excuse for not letting children get to know their cousins. What's wrong with getting overtired from time to time?
Other Mums may have been perfectly happy living a well structured life, but as my children got older I know they wouldn't have wanted to miss the adventures we had together.
Oh and dare I mention that I sleep better with a dc in bed as that prevents dh from doing his full blast snoring. He finds this rather unwifely, but I'm afraid I do appreciate a night's quiet rest now and then. Shame I'm too old for another baby.