ExXB,
I'm a self-employed hotelier these days, I have a price on my rooms, how much do I know the travelling public are prepared to pay? ... Well I don't until it may be too late, I can only guess.
I get many guests of one particular nationality, pertinent to the country I am domicile in, asking if my competitive room rates include a free breakfast to which my answer is always "There is no such thing as a free breakfast".
Similarly airline seats come with a baggage allowance, it is not a free allowance but comes inclusive with the fare paid, now if the airline have got their pricing structure wrong then whose fault is that?
My local airline from a drop-down menu one selects how many adults and how many children are travelling and, moving on, from a further drop-down menu enters dates of birth. If they try to say that kids are not allowed hand baggage then I would try booking the kid as an adult and then see if their date of birth thingy realises that the kid isn't old enough to be an adult.