My BPRC Big Big Hymek runs very happily on two HP Deskjet (~12V permanent magnet) motors. But returning to the question, Richard’s points make sense, and it is frustrating to those of us who enjoy fixing stuff to be thwarted by devious design.
OTOH, it’s not unreasonable for a designer to create something without fasteners, particularly in injection moulded plastics, as clip together or ultrasonic welding are both cheaper than the screw and the person inserting and tightening it. And I’m sure anything that helps the margin on the product is worth considering, be it a batch of 1000 or 10,000.
of course, if as a manufacturer, you produce something that is not able to be stripped for repair or maintenance, you might end up with a lot of unusable stock on your hands, which you can only sell as “for spares or repair”, and that won’t help the business case at all.