My very simple guess is this. It requires more parts, bigger assembly line, overall higher complexity, adds weight, makes the headset more fragile, and so forth, so I’m sure if they can make a design that accommodates the majority of users, it is cheaper to say “good enough” then to design and accommodate for the rest of the potential users
Work for a somewhat expensive automotive brand and yes it is very common. We have cars from $60k to over $400k and beyond, and they all are glued together everywhere you look, that or plastic clips, very little is actually bolted on. Sometimes because in a crash it is better that a piece breaks and fly’s off then to stay mounted to the car, and in (most) other cases, probably for cost reasons. But it is a common thing, and has been for a long while, and if executed right, it is tried and true, however if you don’t have good quality control and workers who don’t care, they’re not gonna mount pieces right, and create a hazard