Obviously it isn't required. It's entirely about control and monitoring habits for monetization, killing the game when they want, etc. Exact same thing with Actiblizz except they went even further so as to scam people into using the RMAH. Stop giving these dicks your money because you're fucking it up for the rest of us!
“There is no such thing as a weird human being. It’s just that some people require more understanding than others.” - Tom Robbins