[gioele]

That part is not part of the law, just introductory text. The law says in Article 5:

«3. Member States shall ensure that the storing of information, or the gaining of access to information already stored, in the terminal equipment of a subscriber or user is only allowed on condition that the subscriber or user concerned has given his or her consent, having been provided with clear and comprehensive information, in accordance with Directive 95/46/EC, inter alia, about the purposes of the processing.

This shall not prevent any technical storage or access for the sole purpose of carrying out the transmission of a communication over an electronic communications network, or as strictly necessary in order for the provider of an information society service explicitly requested by the subscriber or user to provide the service.»

A site can store data on a person's computer only if that person has give its consent to it or if it is technically needed. Your ad campaigns, your A/B tests, your detailed analytics are not technically needed and I want to have a say on whether they are going to be stored in my computer.

Please note that many national implementation explicitly allow for broad mechanism like "accept all cookies" buttons during installations as long they are set or clicked by the user and are not simple defaults.

[ppod]

Whether it is in the recital or the enacting terms is irrelevant, I quoted the recital because it is a little clearer.

The effect is the same - sites have interpreted the law to mean that a pop-up prompt is necessary. I think that the inconvenience of this outweighs the benefit. You might disagree, but don't try to make it sound as if everyone who disagrees with you is ignorant.