Well my guess is of course, the size plays a factor into it. Making something smaller to fit into something is very expensive. Please don't go anywhere else with that last sentence...
The Switch is a blessing and a curse to itself in terms of design. The screen really dictates how large the controllers could be for the Switch to be appealing and thus the Joycon are really small. Fitting that much tech into such a small form factor has to cost something...







