And if it took any longer, I'd make this journey even less.

302,382 people flew from SFO to Europe in May 2016. That's a lot of people. Almost 5% of the Bay Area population and there are 2 more international airports in the region. [0]

[0] http://media.flysfo.com.s3.amazonaws.com/media/sfo/media/air...

Collectively far more people are flying from San Francisco to Los Angeles, San Diego, Phoenix, Las Vegas, Salt Lake City, Portland, and Seattle each month. If they could all show up at the airport 5 minutes early, hop in a tiny drone-jet with 3-4 other passengers and take off, not having to deal with security would be icing on the cake in terms of convenience.

I don't think the parent was suggesting that his idea should be the only solution... just that it would be a solution that would work for many use cases (and could exist in combination with larger long haul flights).