Internally-routed cables, not just the abjectly daft through-the-headset variety but the ones that go under the bar tape as well. One thing I used to love on my old 3x9 setup was that the gear cables sprang out of the sides of the shifters and I could rest my thumbs on them as an alternative to wrapping them round the bars. Now there's no thumb relief and I've got to unwrap the bars to put in a new outer: what rubbish!
Ditto profiled "aero" seatposts that you can't clamp anything onto. Seatposts should be cylindrical and 27.2 mm in diameter, as God designed them.
You can sell an arsehole anything if you call it aero.
And not aero, but let's include sloping crossbars that make the frame too tight to take 2 x 1-litre bottles. Call it stiffer if you like but the change was really made so that manufacturers could save money by making bikes in 4 or 5 sizes labelled S, M,L, XL etc rather than to real measurements with 1-cm increments between sizes. And with that that great long seatpost, is the setup really any stiffer?