Nothing in that article is a reason why they are introducing the porn filters in the UK
OP opened a can of worms. Seriously. (No, really: seriously.)
Arguing that it's art? That it is in itself valuable to culture as "low art" is? This isn't a question restricted to the UK, and it's one we need to get philosophically astute about pretty fast. So, again: Porn is not the problem — you are.
Whatever it is, analogies to automobile accidents and art, in any sense, is a stretch beyond palatability, and makes this entire discussion look entirely intellectually one-sided. I think such talk is a disservice to the discussion, and maybe porn should be blocked on those grounds alone, for I am quite sure OP's aesthetics are common.
This is ostensibly a "think of the children" move, it has nothing to do with aesthetics or art, low or high. In reality, it's probably also an old school conservative play to "clean up" the filth.
On the list of things children should not watch people having sex should really not be close to the top. It is just sex. After breathing, drinking and eating it is one of the most natural and common activities on earth. A coyote trying to smash a bird with an anvil seems a way less appropriate thing for children to watch.
The UK has more of a problem with children watching the weird unrealistic sex portrayed by the US porn industry.
[1] http://skeptics.stackexchange.com/questions/7668/is-the-inco...
This.
Now, why is the US unique here?
US TV shows have to censor their language unless they're broadcast on cable or satellite.