That's their choice - the comment I replied to phrased it as if every airline charges extra for any baggage of any kind, not that cheap airlines charge for 'extras'.
> oddities in American flights
And you framed it as if every American airline charges extra for any baggage of any kind
You missed the preceding "another case of". As in an example of odd things that can happen.
I didn't proclaim "American airlines charge you extra" did I?