I'm a parent who took my child in a stroller before they could remember. Why? Because we go very often and I don't sit at home until they remember things. I find that argument that the kids don't remember kind of silly because no one should ever just sit at home from things because kids don't remember - because the parents sure do.
I do sometimes think that parents push too hard to have perfection or go non-stop so the kids are miserable, but every family is different and if they have fun, I don't care. That's why I find the whining over an hour also a bit silly. If you cannot, as an adult, make it back in an hour, it's not the end of the world. No ride is that important. That said an unruly child or two shouldn't prevent a swap. Parents also should be able to just swap immediately after in almost all cases. Maybe a tiny percentage will really have something major happen (child severely hurt or the like) but meltdowns don't count in this case to me. That's on the parents for not dealing and swapping. Obviously I'm a parent and I am in the middle of taking school-aged offspring. So I'm not that out of touch with reality. I'm not going to judge parents whose kids melt down or anything, I just don't see things on that level as a valid excuse.