With a single USB OTG cable I can connect almost any peripheral to my phone, including my XBox 360 controller and my endoscopic camera. Why not a monitor as well? Why do they have all these other weird non-USB connectors like HDMI and DVI? I'm sure there's a good answer from a developer's perspective but from a user perspective or makes perfect sense for there to be a single connector to rule them all.
Edit: another example is that sometimes I connect more than one mouse or keyboard to a single computer. Imagine if there were still dedicated ports for each type of peripheral – would I need to buy a special motherboard with two mice slots? Or a mouse port expansion card? What a nightmare.
Eventually we'll reach the dream and it will be great, but there was no need to jump in the pit of spikes on our way there. It wasn't blocking the road, it wasn't camouflaged, it was out there in the open, and the USB-C guys decided it would be fun to jump in. Why?
Now we have those smart peripherals and 20x the complexity. Thanks Intel. And thanks Apple for making Firewire too expensive.
In my alternate universe my home AV equipment networks with GPIB and 1Ge PoE with SCTP.
Only certain engineers. Don't group the ones who love gratuitous complexity and "value engineering" with those who think complex standards like USB-C are a horrible idea and would rather have separate and simple interfaces.
There's a reason RS-232/485 (along with good old D connectors) are still extremely prevalent in non-consumer equipment.