“Not a bad idea” if you’re the one making the money, that is.
Would you think it’s a good idea if expanded to other things? How about your hammer coming with a license that if you build anything with it, you owe royalties to the manufacturer of the hammer? Or your car manufacturer saying that since they make your commute so much easier than other cars, they’re entitled to 10% of your salary – but you’re welcome to use another car if you don’t like it (spoiler: all new cars come with similar licenses, but you’re welcome to take the bus.) Do any business on your computer? Microsoft now wants 10% of your salary because time is money, but if you don’t like it you’re welcome to use something else. And how about your cell phone?