First of all I want to apologize to anyone named Karen or Ken. You didn’t do anything wrong and I don’t know why your name got associated with people who are hard to be around.
Having said that, we have all encountered “karens” and “kens”. People who are self-absorbed, demanding and entitled. That’s bad enough but then they go ahead and complain loudly and make everyone around them miserable too. Eventually they usually need to speak to the manager at the store/restaurant/etc. Exhausting!