In my opinion that's is not a problem. One thing that I understand is money should have value which is intrinsic value or non intrinsic value. I think that will not happen. The creation of money should fulfill some criteria, I think if someone create his own money but nobody want it then it is just a trash for other people. I think there is should be atleast another person who accept his money then it can be considered as valuable money. Honestly I don't like to think complicated things too much, I prefer like to think about something that exist and what I can do with it. Now, there are cryptocurrencies and I can make some profit from it. So I like to learn about how I can maximize opportunities in cryptocurrency investment.
Depends on what others will accept. If a company like an e-commerce site creates a crypto coin, they may only accept the coin they own so clients will likely be forced to buy the coin that this e-commerce owns thus will set an intrinsic value to the coin.
If amazon will launch its own coin, it will also work this way. They will not accept any other coin but their own. If someone or any other store accepts their coin then it's their option.