Plus, if what you're talking about is the experience of pregnancy and giving birth, then it makes sense to focus on that, rather than on the much wider experience of motherhood.
To me, it's more confusing that some people insist on using less precise terms because they find the idea of inclusivity offensive.
We're 100% in agreement on the offense issue though. I don't get why anyone is offended by what someone else prefers to be called. Take the politics out of it and that's like being offended that someone says their name is Steve when you absolutely refuse to believe they are called anything other than Bill.