Closing off the battery compartment allows for five things:
1. Better physical engineering options
2. More options with battery shape
3. More physical space can be taken up by battery, rather than room for the battery
4. More options for the physical location of the battery (under the screen for example)
5. More onus on the OEM to use quality batteries - because they're replacing devices, not batteries if these things fail.
If the trade off to having to charge each night instead of hot swapping is worth it or not is up to the individual. My gut says that most people are charging every night either way. When it comes to batteries, we really need the focus to shift to batteries that last for many, many days or weeks - not measured in hours where some users are scrambling for chargers. Sealing off this compartment is a step (not a big step, but a necessary one) into allowing for that transformation.
MicroSD support is one I'm personally thankful is not included, but I do understand that some people enjoy using that functionality. To me MicroSD will always represent a security and stability concern that doesn't exist otherwise, as well as a needless opportunity cost - every OEM that includes it is adding custom code to do so, carving out physical space and materials within the device, spending hardware and software engineering time, buying the parts, testing, etc. Even if that is only a few extra cents per device, 10 million devices in and that's some money that could have gone towards features in the device software or other benefits to more users. Again, obviously some people want THIS feature, not others. That's fine; I'm not one of them and most users are also not those users. It is smart for OEM's to play to the market(s), not to the forums.
I will be sad if we get to a place where those options exist on no devices. I live in the US where these things aren't necessary for most users. In some markets, these options are both very necessary and should remain viable until they are not needed. As long as these decisions are analytically market driven, there is no conflict IMO.