I think it makes sense. The power cable is usually fixed and not moved for a desktop computer. The same holds true for an ethernet cable. It's fixed and plugged

I think it makes sense. The power cable is usually fixed and not moved for a desktop computer. The same holds true for an ethernet cable. It's fixed and plugged into the wall. So both ports that are used for fixed cords plug and that plug into a wall are located at the same spot. The ports on the computer itself are for devices that you might plug and unplug on a daily basis. Peripherals, charging cables, USBs etc. This makes a lot of sense the way its setup. Fixed cables are grouped and separated from "free floating" cables. From my own experience, most people end up using wifi anyway at home and in office regardless of the device type (desktop/laptop). This way the least likely to be used port is also separated from the device and also means that if you need to for whatever reason swap one iMac with another, a single plug into the new iMac will connect power and ethernet with no other setup necessary.