Hmmm, strangely enough in this country children are not able to know whether they want sexual relations until they are 16, and yet we seem to think they are able to know their minds enough to be criminally accountable from the age of 10. The fact is, all children mature at different rates - some are emotionally aware before 16, some less so. Some of these so-called paedophiles are probably on the less emotionally aware scale, whatever their age.
The line I quoted was about paedophilia which is about pre-prubescent children so the age of consent is irrelevent.
Also there are different bands of the seriousness of offending in the UK based on the age of the child and a lot of discretion about prosecuting underage relationships - as there should be - as relationships are complex. There is a huge gap in the treatment of someone who rapes a 5 year old to someone who dates a 15 year old.
Those under 16 are not considered to be unable to know whether they want sexual relationships - that would be absurd - instead those who sleep with them are however considered to be at risk (though not much) of being prosecuted for it.