The only bad side I foresee is that with the poor quality control in these factories as it is lots of these unassembled kits would probably arrive missing parts.
As a non-sequitur, I used to be into Radio Control cars that you had to assemble yourself nut and bolt and bought a few kits from Associated (American company) and Kyosho and Tamiya (both Japanese) and never had even one nut or washer missing. Good logistics and quality control.