I've been flying my family overseas from the time my children were infants, and you're right that the fees are insignificant when you're paying the current rates to fly 4 people during high travel season.

But I'll just add another casual observation that people travel with way too much shit.

For a family of 4 we've never needed more than 2 suitcases, and maybe only one is packed to the max. If I had 200 pounds of luggage (+ carryons) for 4 people staying 2 weeks in Europe I'd probably be reconsidering a few things.