Obviously, 9 is ridiculously low and would be 'legalising' rape of children.
However, I wonder how keen they would be for 9yo boys to be sexually active too? Are the similar age boy-children and their 'rights' in their consideration as well - or is this just a case of older men determined to abuse girls to get their jollies?
Even at a 'standard' western age of consent, I'm still very wary indeed of mature men in the UK going after 16yo girls.
However much they insist "It's all legal!" and make those with an issue with it out to be crazy prudes, it's a huge red flag to me when significantly older men are so keen to eschew relations with women of a similar age - or at least fully mature adults - In favour of girls who are still technically children - legal or not.