The argument against it is that by visiting a site you are initiating an exchange as determined by the site operator. In the case of YT, you are watching a video you want to, and must in return watch ads or pay for a premium subscription. The technical details, according to this argument, are invisible to most people and therefore irrelevant. This is, of course, a stance that only makes sense to someone without a real sense of ownership over their computing devices, i.e. to someone who views computers as appliances that are used to consume services.