I always find replies like this interesting. Our baby girl is very mellow. She has travelled now on 8 international F segments, and on a recent trip SFO-LHR-DXB and back in F, we got remarks at immigration from fellow F passengers to the likes of "oh, I was so scared my flight would be ruined but your baby is SO GOOD...how do you do it?".

On the other hand I myself have had my flight ruined more than once by arrogant, boistrous businessmen. I recall a QF flight SYD-LAX in F where 6 seats in the cabin were taken by testosterone laden dealmakers who insisted on getting drunk, illegally tossing around and sharing a bottle of meds, and shouting across the aisles at each other, basically ruining everyone else's flight until they finally, thank God, passed out from Xanax or whatever. I wish people like this (and probably their ill raised kids) were not allowed in F.

Its all about the people. To generalize that some class of people should be barred from a cabin, it just doesn't cut it IMO.