And yet, this is possibly the first laptop I've come across that features a non user-replaceable battery, resulting in at the very least energy used in shipping the unit back to Apple for replacement, and at worst premature disposal of the technology.

Cost and size are good motivators in making people maintain things. A new iPod battery is $29 and the iPod is small and inexpensive - people are far more likely to risk "trying to fix it" when at worst they lose a $300 last generation gadget they wanted to upgrade anyway. Far more MacBook Airs will reach the end of the battery lifespan during the machine's useful life.