There is no technical reason why it can't be as short as you like. But obviously it must be well constructed, so that it does not develop an internal short or open if stepped on, pulled, etc. And if it lacks UL approval, there could be a problem with your insurance if a fire ever originated as a result of overheating of either it or what it is powering.
why do companies not make a short cable?
Lack of demand, I suppose.
Regards,
-- Al
