Re: Now i hate apple....
Apple don't say that if you discontinue Siri then they will delete all your data, only that they'll delete the non-anonymised stuff. The article even has the relevant bit in bold:
If you turn off Siri, Apple will delete your user data, as well as your recent voice input data. Older voice input data that has been disassociated from you may be retained for a period of time to generally improve Siri and other Apple products and services.
As to your related point about whether voice data can really be anonymised, they could technically just be keeping the first-level stuff about pitches and rhythms that they extracted from the sound recording, which would identify you only in the same sense that written text with no associated author could identify you, but probably they just mean 'we won't store further user details with it'.