as several posters have said, booking seats does not even guarantee you get them. but what astounds me is this "I'm alright Jack" attitude which prevails. why on earth would other passengers not swap, to help out a child in need?
a couple fo years ago, we flew to Australia. we are frequent flyers, know the pitfalls of travelling by air, and know what we need to do to ensure as smootha flight as possible. following a hideous time booking seats on a BA flight to California the previous year (the computerised seating system kept moving dd1 downstairs out of the top deck business class section, on her own - she was 3) we knew we needed to keep on top of it all.
we used a travel agent, and told them they woudl need to be on top of ensuring we sat together (dd1 was 4, with severe ASD. dd2 was 2, and still bf. both needed to be with me, preferably)
travel agent stuffed up, and we were seated for one sector in 2x2 seats, eg seats 1A and 1B, and 2A and 2B. since we were travelling business, this meant that one dd was not going to be able to see me at take off - big disaster.
the cabin crew asked the entire cabin (we were also travelling with dsd and dss, which meant that any other couple swappign would ensure we could have 4 seats in the layout we needed) if a couple would mind swapping, so that dd2 coudl sit next to her mum.
not a single couple moved. the cabin stewards were
- they had never seen a situation where not a single person was wiling to swap (bear in mind this was business class on an Airbus - all seats are spacious, have good storage etc). and due to their refusal, they al got to spend the first 30 minutes of the flight with a screaming dd1 and dd2 (dd2 upset becasue she could not see me, she was jsut a baby. dd1 upset because she could hear her sister was upset, and could do nothing about it). the man next to dd1 (well across the aisle) got really narky with her and told ehr to be quiet (dd1 wearing a t shirt saying "I'm autistic, please be patient with me") - and was told in no uncertain terms by the cabin manager that since he had refused to help her out (by swapping seats with dh and dd2) he could put up or leave the cabin.
honestly, people get so precious about where they sit (as in, "I must be in seat 2C or similar") - why on earth people would not move so that a baby could sit with her mother is beyond me - surely a recipe for disaster if you want a peaceful flight?