No I would never change my babies diaper on a bench in public.
A baby deserves privacy as well just like adults and nobody should be watching the diaper change.
If I did need to change my babies diaper in public though I would make sure to cover him up with something such as a towel so that his diaper change is not seen.
I made sure to keep my kids in fresh diapers before we went out and usually with the diapers which were Pampers baby dry the kid could easily go 3 to 4 hours in a wet diaper before it got to wet where it leaked.
If the child pooped then I would usually wait for 30 minutes or so to get to my car or back home to change the diaper.
Or I would drive to the park where there is a restroom and change them their.
30 minutes in a poop diaper or wet diaper or even an hour is not gonna harm them.
I once saw a mother in Walmart parking lot announce loudly that her 1 month old daughter had crapped her diaper and was making a huge deal about it.
She proceeded to take her diaper off right there in her infant carrier and car seat and continued wiping her and changing her and basically making fun of her for pooping her diaper.
I so wanted to slap that lady but I held back.
No one wants to see a baby get changed and a baby should not be shamed or made fun of to strangers for pooping a diaper.
She also had a 2 year old boy with her who was also in diapers and she loudly said to him did you poop your diaper too lets check your diaper.
She then proceeded to pull his pants down right there in the parking lot for all to see and checked his diaper.
He hadn't pooped but he did have a wet diaper and she then took his diaper off right there and wiped him and put a new one on.
She left his pants off and then told him to get into the car.
She was basically making fun of the 2 year old as well for wearing diapers and wetting them.
I could tell the 2 year old was embarrassed and ashamed.
I felt so bad for him and the little baby.