JJ you're male I think?
I assume you've been in situations eg theatre, gigs where in a break there's a massive queue for the women's while the men swan Inn and out and get to get a drink from the bar while the women patiently queue and get no drinks (unless they have a man with them to get one for them)?
Why do you think this is ok?
Please note the article also refers to public sector. So employers in the public sector and things provided by them. Eg the tube. Why do you think it's better to have single sex for men, and women's provision altered to mixed sex? Out of interest. That's how it works at my tube station. Men can go anywhere including choosing male only. Women have no women only any more.
Can you explain why you think the law saying there must be single sex provision for changing and toilets over age 8 in schools in wrong. Can't you remember being a teenager? Why are you keen to have both male and female children and teens out in such an embarrassing situation?
Interested to hear your reasoning.