I agree with you. What you refer to as a monopoly is more a case of the business being being dominant and good at what they do.
"Sort of like the Soup Nazi on Seinfeld" Their product or service is superior to the point that they dominate the competition and set their own rules.
You can either play by their rules or play somewhere else.
A business that can dominate their marketplace and set the rules as they see fit did not get to that point by accident.
They generally have a good reputation and many satisfied customers that keep coming back.
Their core service/product is generally so good that consumers ignore or deal with any quirkiness or rules they do not like.
There are CG's I frequent the have rules or policies I don't agree with but at the end of the day I keep coming back because overall I always have a positive experience.