This is a question that I came across earlier this year and it made me think, this is my response.
I know it's quite hard to come up with a suitable awnser when speaking about our own experiencs when compared to other people wich happily is something that I have now done and it's based on my memory of being a child.
As I wasn't out of Diapers/Nappies, untill the age of 9 & half due to verious reasons.
However I do believe the sender is it's true babies/toddlers and children like wearing diapers/nappies as long as they can because of these reasons.
My awnsers to this question are as follows:
Reasons be for a like or love of diapers at an early age/childhood.
1. Being loved the feeling of being totally relaxed knowing that they don't have to worry about accidents at anytime of the day or night, see comment no:# 8 for more information.
Also the smell as baby diapers/nappies tend to be scented and that was a real turn on as a child for me because I enjoyed the feeling of not only wearing them but also smelling that famillar heavenly baby fresh fregrence.
2. Self Invincibility the feeling of security and protection and that famillar feeling about being cared about knowing they are loved this can be because of the fact when your in a diaper nothing feels like it can hurt you intact I almost felt like a turtle in its shell if something bad happened I had somewhere to retreat as I knew I could count on protection not just from the outside world.
3. Comfort that feeling some times you get is almost in discribable for instance even the soft cushioning padding between the legs when you sit down has its own rewarding feeling as no surface feels too hard or uncomfortable and the fact when you sit down or crawl it moves with you and trust me on this point well that's a feeling that I have never forgotten about as it's pure bliss or heaven at least psychologically speaking.
4. Vanaty: the look you can't say toddlers don't like the look of a bulky diaper/nappy between the legs, as specially if it has printed cartoon characters or other images on it however when I was a child any diaper printed or otherwise would do speaking of seeing images of one's self in diapers as specially in front of a mirror.
And then getting a instant gratification or happy experience out of it as know I did every time I caught my reflection in a mirror, although this is more a self vanity thing so maybe not in every child's case.
5. Scence of Normality it is not abnormal for wear them as other children they meet in nursery groups are also wearing them, so no shame or stigmas which trust me, is the best thing about being a child.
6. Sents some times the smell of a clean diaper/nappy has a appeal to a child as baby ones tend to be sented and this can make them want to wear them, again I know every time I smelled that familiar pampers scent or even baby powder and cream as it made me feel happy.
7. Being able to simply just relax and sleep easier was a plus side of wearing them as it meant that I could just curl up any-where and take a nap without virtually a care in the world and that I could get a chance.
8. Practicality the fact you have the freedom to go and use them anywhere and not have to worry about anything, this was and is still a great feeling even-though nowadays as a adult I am the one who changes his own diaper/nappy but still remembers how it felt all those years ago.