It's more about voltage than power, so you are wrong that they necessarily drain the battery when plugged in . Anyways, this isn't new at all, it was the same with PowerBook Duo.
Same deal with the lack of keyboard texturing on Macs, providing a flat surface for bacteria, oils and dirt to collect on your laptop's keyboard. Other manufacturers commonly add an anti-microbial texture to their keyboards, which also wards off most of the grease you see on Mac keyboards.
Personally, I don't remember owning a battery removable Mac notebook between the PowerBook G4 to the MacBook Pro that couldn't function without a battery while plugged in.
Never seen significant puffage in the used/broken Li-Ion battery packs I've rebuilt either, so presumably that is moderately unique to Apple?
So, that's drivers, batteries, and keyboard-coatings; what's next?
Never said that battery failure was something that only occurred with Apple, just the way they fail (puffing up) was something that has happened to myself and two of my friends, meanwhile these 5+ year old battery packs from HPs and Dells that I've been pulling apart had a cell or two fail to retain a charge, but they don't significantly expand in size usually.
sudo nvram -d fmm-mobileme-token-FMM
Clean your keyboard more regularly.
Just touching an Apple keyboard gives it a slight grease, despite regular cleaning. You don't get that on other keyboards, as they are textured slightly to prevent it.