That does seem an odd thing to say too.
The filters do a reasonable job and the network level ones are the simplest to use, the Sky one is nice as there is a blacklist and whitelist exception list option. So if you want to block everything, but open up a site for a teenager to do homework you can.
The Sky system also makes it clear if a site is blocked, so then people can talk about it and then the lists be rejigged.
Turning off/on categories is simple enough just log into the portal and change the setting, which lots of the press coverage is not mentioning, reading them it is as if once you set the levels you can never remove them.