I can't remember consumers demanding glued-in batteries. I think decisions like this are taken for all kinds of reasons (CEO preference, ease of design and assembly, lock-in, etc) and then presented to consumers as packages that they can accept or decline. But it's too simple to say that this is solely driven by consumer choice.
Consumers demanded slimmer designs over glued in batteries, soldered RAM chips, etc. So the market responded by gluing in batteries and soldering ram. In a way, the consumers did demand that.
