Depends on the world you travel in. And I don't mean third world, first world, I mean the sort of places you have to visit.
Most defense facilities will NOT have wifi, and their meeting rooms will still have projectors with VGA in only. For travelers in the world that I inhabit, all those ports are a necessity. We would even still love to have a DB9 serial port because we often connect to embedded systems with serial consoles.
You and I live in different worlds, even though we both probably work on very technically involved things.
That being said, when I am in meetings, or on the move for work, I don't carry dongles with me. Pure laptop for me. All of our meeting spaces have Airplay compatible projectors, so I sit down, make sure I am on wifi and connect to the display.
Transferring large files? We've got 1 Gbit to our desks, I can sling data from our Denver location to our St. Louis location at almost 300 Mbit/sec sustained. Also, wireless N/AC throughout the building.
In the world where you no longer NEED those ports, having a smaller lighter laptop makes all the difference. I already don't carry dongles with me, the new laptop with less ports wouldn't change that.