I think it's much more about engineering and design tradeoffs. It would simply not have been possible to make an enclosure as robust as the one used now in the unibody machines had they incorporated a removable battery.

There may be some deluded people at Apple that think that their way is the only way, but in all my dealings with people at the company, they know fully well when limitations exist. They're simply targetting the most consumers they can. The others, usually the more advanced anyway, can find their own way to their solutions.

There are plenty of third-party replaceable batteries available for older machines as well, and they come with their own warranties. I'm pretty sure that in the US consumers are covered by the same act you mentioned (from Apple voiding their warranties). Of course that's not likely to cover a defective third party product directly or indirectly causing damage to the computer through something like fire. But then you might just have a lot more to worry about that a broken computer.

I like the current design because it fits my usage very well. I absolutely agree that there are people out there that won't find the situation ideal. However, the battery life is significantly improved from previous generations, so those affected customers should number even fewer than ever before.