This was the last gasp of Johnny Ive. And yes, it was terrible. It got us ending the incredibly successful Macbook Air for the too-compromised 12" Macbook (1 port, remember?), the pointless Touch Bar and the terrible butterly keyboard (remember how dust could kill it and I'm sure Apple spent a fortune on replacements?).
Why did we get all these things? It wasn't just thinness. It was to raise to Average Selling Price ("ASP"). Someone at Apple decided the ASP was too low.
Ultimately the Macbook Air came back and it's really the SKU the most people should buy.
I collect the 12" macbooks, even today. It really only needs one port; the vast majority of people never plug anything but power into their computer ever. I would pay huge sums for a modern Mx 11-12" ultralight macbook with a reliable keyboard.
They did not take the MacBook Air off the market when the retina Macbook 12" was released. The MacBookAir7,1 was released a month before the MacBook8,1. The 7,2 came out 2 years later as a spec bump not because Apple abandoned the product, but because this was the same time Intel's tick-tock schedule went completely off the rails.