Hands-On with the HTC One
Replying to: Unfortunately... by Slammer
Certainly there are several valid reasons why a user might want a removable battery.
But there are also several valid reasons that many companies (not just HTC) seal the battery inside. The biggest one is that it helps them cut the size of the whole down. They can make the battery an unusual shape and/or put it behind the circuit board. That's what HTC does now, and it's how they get the thin design with the curved back. There's no way to do that and have a removable battery. Plus when they seal everything up tight it makes feel more solid and high-quality. It also helps keep dust and moisture out, improving reliability.
So, while a removable battery is nice, I think it's important to acknowledge the trade-offs and why companies don't always make them removable.