"Who removes the phone battery because they are 'that' worried about being spied on?"
In the case of Samsung phones, the person who stole it. Otherwise it can be tracked with Dive.
A fixed battery is only really bad from the point of view of replacing faulty ones. I could live with that. It's the lack of microSD slot that means I, like so many others present, will be moving to a different manufacturer when the time comes to replace my S4.