Apple always get rid of stuff earlier than competitors and it always winds people up whether it's Flash, optical drives, ethernet ports, etc. The Macbook is where they see general consumer laptops going in the next few years - it's not like they're forcing anyone to buy it since they're still selling two other lines - stripping things down to the bare essentials of screen, keyboard, display. Back in 2008 when the Air came out, the white Macbook was cheaper, more powerful and sold more. It wasn't until 2010/11 that the Air went down in price and became what we know now, killing off the white Macbook. 2015 and the roles have reversed.
Battery life will get better, speed will improve (the Retina 5K iMac is first-gen and can stutter/lag a bit too, despite being way more powerful), but the design philosophy won't change. If we look at what people (average joe) actually use ports for:
USB memory sticks - cloud-based file-hosting services are making these more unecessary as internet access is also increasingly 24/7, and things like the new Photos app on OSX mean whatever you take on your iPhone/iPad is uploaded anyway. Music is streamed. Media professionals who need to transfer large video/audio/image files will be using a MBP (hence why no Thunderbolt on the Macbook) anyway.
Headsets - wireless/bluetooth headsets are taking over (e.g. the new Beats which come in matching silver/gold/space grey for the Macbook).
Webcams - all built in now
Restoring a device - Internet Recovery
Large external storage - how many people carry large drives around with them these days other than perhaps media professionals (covered above)? Again, music, photos etc are cloud-based/streamed.
USB mice - who uses these now? Out and about, who even uses a bluetooth/wireless one?
External monitor - probably the only compelling use case but even then, using people like my sister as an example, she doesn't have room in her flat for a desk and sits on the sofa with her Air. Most people I know who have an external laptop for their display have a specific reason for it that goes beyond web/email/skype etc.
SD card slot - people with DSLRs etc will be wanting more than a barebones computer (i.e. not the Macbook). Average joe takes his photos with his phone.
The people actually NEED ports I suspect are the sort of people that require a more powerful machine anyway (hello MBP).