When you first buy all your parts for the very first ttime for your first build you say this is gonna be one hell machine you build it turn it on everything works then you look inside your case still turned on for a test run and you see your graphics card not spinning its fans you unplug it plug it in still not working! its likely a defective part or other times it might be your hdd or motherboard or potentially your PSU and you get really mad and feel like ripping your hair out. dont worry this is why manufacturers arent as perfect and sometimes they might mess up but you know everything gonna be alright because its still got its warranty period then your all set the next day when you send it back for a new one a week later it arrives and everythings brand new like you just got it.
At least some people got time to occupie themselves when your waiting for a part to arrive wouldn't you agree?
Plus I wonder what will happen to those defective parts they probably lose some money or they probably just scrap and start again.