Illegal? You don't own the rights to the app- the developer does. They can do whatever they want with the app. All you did was rent a license to use the app.
Delusions of entitlement are disturbing. "I must be treated like royalty for spending a buck or two on something that isn't a small bag of chips! Harumph!"
Welcome to the reality of digital purchases. You own nothing, and the creator as well as dispenser can do whatever they want with said item. Amazon, Apple, Microsoft, Sony, etcetera have shown this to be true multiple times.