the built-in battery is what makes an "ultrabook" possible. lenovo still makes laptops with removable batteries if you really want such a device. consumer choice is not really the hallmark of the apple brand.
everything inside the chassis that isnt pcb, heatpipe, or fan is part of the battery pack. it takes up almost all the otherwise unused space inside the device. how would you design a battery door for this chassis that doesn't decrease the size of the battery or make the whole thing much bigger?
I know it would never happen, but I'd be ok with the battery pack living outside of the laptop itself, almost like an external hard-drive you plug in via USB-C. Could probably install a mount on the back of the screen it could clip onto.
My main point is that I'd enjoy the ability to cut full power to my device at my discretion. I've never been a fan of all the Mac background activity when I close my screen (auto-downloading updates, wake for wifi, etc).
I understand why you would want this, but obviously apple is never going to let something this ugly wear its logo. maybe if enough people demanded it, they could add a physical battery disconnect switch on the bottom as a $1000 option.
as I said before though, laptops with removable batteries are still being made by companies like lenovo. windows is not great if you're a paranoid person, but thinkpads usually play nicely with linux. if you're willing to carry around a laptop with an external battery pack and clip it onto the back of your screen, I feel like you should be willing to deal with setting up linux on a laptop ;)
edit: I'm actually not sure there are any current gen thinkpads with fully removable batteries. truly a sad day. you might be limited to enormous gaming laptops.
What if the laptop was hollow where the battery cells are. And what if something that looks similar to the Nokia 5165 battery would be put into this place. The battery would contain the same bag shaped cells.
you can't just expose a package like that to the user. user-removable batteries need to have a much sturdier (ie, thicker and heavier) package to prevent damage to the cells (major fire hazard). probably the chassis itself needs an additional layer of plastic to protect the components that would be exposed when the battery is removed. on top of all that, you need a robust latching mechanism that can withstand clumsy users removing and reinserting the battery over and over again. the end result is a much thicker and heavier device.
