The argument often given is that we should 'be kind' and let trans people 'be themselves' and 'they just want to pee'.
That sounds all very fair, doesn't it, and I don't think many on here would object to that.
HOWEVER, unfortunately, that is not all that gender extremists - many/most of whom are straight men and not trans at all - are asking for. Many trans people are horrified by the things that are being demanded in their name, and say so publicly.
What these gender extremists are demanding is NOT equal rights for trans people (which they already have in the UK), it is the 'right' to take away women's rights.
Hence, for example, demands to stop using the word 'women' (but not 'men', making it clear it is misogynists demanding this, not those interested in equal rights). Demands to end women's single-sex spaces, from refuges, to toilets, changing rooms etc. Demands to end women-only shortlists, women's sports. All these are things that women fought for decades, to ensure women's safety and equal rights and opportunity to take part in everyday activities that men take for granted. Attempts to end these are NOT progressive - they are extremely reactionary and regressive.
In addition, your dh suggests this is like the fight for gay/lesbian rights - but it is the opposite. Instead, gay men and lesbians are being told they MUST accept sexual partners who claim to be trans but are of the opposite sex, or else be branded transphobic. This is what is referred to as the 'cotton ceiling' and is basically conversion therapy and rape culture. Far from being just like those who supported gay liberation in the 70s and 80s, gender extremists are like the religious extremists who opposed gay liberation. Except now their religion is genderism. Instead of calling gay men/lesbians sinners, they call them transphobes, but the meaning is clearly the same.
Genderism is a violently homophobic movement - lesbians who refuse to sleep with people with male bodies who claim to be women are cancelled, ostracised and set upon. If your dh really cares about the rights of gay men/lesbians, he will listen to the voices of all those LGB people, including the many who were leading the fight for gay and lesbian rights in the 70s and 80s, who have called out this new gender extremism and set up their own organisations to fight once again for the rights they thought they had already secured - all those behind the LGB Alliance. Did you/your dh read the recent BBC article on the cotton ceiling? If not, you/he should.