I saw the original post last night, but I did not want to be the first to respond.
I feel very differently than each of you do and I do not have children and never will. That being said, I do not refute the fact that it is safer for the infant or toddler to be secured in his/her own seat. That's proven.
In my opinion, there is no valid argument to compare restraining a child in a ground vehicle vs. being restrained while airborne. Just think of how many hours a child, before the age of 2, spends in a car vs. on an airplane. The chances of serious injury or death resulting from an aviation accident is infinitessimal (sp?) compared to an auto accident.
While I think it would be great if the parent chose to purchase a seat for his infant/toddler, it is totally unreasonable to require that those hundreds of dollars be spent on the extreme unlikelihood that an injury/death would occur by being held when the injuries would be less severe or non-existent if being restrained in his own seat. It's simply cost prohibitive for too many young people with children under the age of 2.