Here’s why it’s more than just an annoyance: Because it has a non-removable lithium-ion battery (see iFixit’s teardown), it locks-in this device’s fate as a disposable accessory from the date it’s purchased. Not only do all batteries have a limited number of cycles, but, unlike older battery tech — it’s best *not* to drain a lithium-ion battery completely. Apple’s design forces users to shorten the battery’s life expectancy, by using it until it requires charging, or disallowing charging while being used. Whereas — if the charge port had been in the front — the user could us it like a wired mouse once the battery’s health became poor.
*This wouldn’t be as big an issue if the battery were replaceable.* But as it stands, poor design has unnecessarily tied the longevity of the hardware to the battery’s life, making it the least sustainable design imaginable. Come on, Apple :(