Sex matters. Biology is not bigotry.
My life has been shaped by what my female body does, what male-bodied people have done (or could do) to it, and the judgements, assumptions and limitations placed on me because of it. I have every right and expectation to be able to discuss the physical, social and political implications of being biologically female with those who share this experience. On this, I stand proudly alongside my Spartacus sisters.
With regard to comments about individuals, my view is this:
When somebody with a prominent public platform states a political opinion or publicly behaves in a particular way, they do so in the full knowledge that their opinion/behaviour can be discussed, dissected and opposed by members of the general public. If people believe that this opinion/behaviour is influenced by factors such as that person's sex (or age and experience, social position, personal wealth etc etc) then this will be mentioned because it is relevant.
I see a difference when it comes to people's personal appearance. For example, if Transwoman A has bad skin, I think it is rude and unnecessary to comment on this. Any disagreements with Transwoman A are highly unlikely to ever be about acne, so I would class this as a personal attack.
However, if Transwoman B is dressed as a little girl, then I think this is relevant. This indicates that Transwoman B has a particular sexual fetish which they like to carry out in public, and decisions influenced by that sexual fetish may put women and girls at risk.
Similarly, if Transwoman C is dressed in an overtly masculine way, eg suit and tie, very short hair and a beard, this is also relevant. It signals that Transwoman C is a piss-taker, who takes delight in the discomfort they cause by being obviously male in situations where women and girls are vulnerable.
Transwoman C's appearance also highlights just how easy it would be for a predatory man who is not trans to do exactly the same thing, and to do it with government backing. Their appearance is relevant because it demonstrates that we cannot tell the difference. And if we cannot tell the difference, how do we keep women and girls safe without excluding all male-born people from areas where women are vulnerable?