Just like most of the anti-terror security theater, it's not about being effective in any way, it's about slowly getting the general population to accept increasingly repressive measures and a tighter grip of the "ruling class" on society in general.
Once filtering has been generally accepted, they can gradually start figuring out how to censor the things they really don't want us to see (and guess what, it isn't porn) without having to worry about further social or legislative hurdles.
There is no technological gap between "us" and "them". There's a gap in political savvy between "them" and "us", and we're on the wrong side of that gap.