I'm surprised at the amount of people here confusing carriers with car seats. It seemed obvious enough to me in the article. It's about wearing babies on the plane, not babies sitting in their own seat.
There indeed seem to be a lot of folks commenting who think being able to safely have a car seat on a plane would be a revolutionary change, when that's the part that's a solved problem.
I've updated the title to include "babywearing" to try to make it clearer.
It isn't that surprising given that hackernews tends to skew tin demographics towards young men. And people who don't read articles but have strong opinions on everything.