How do you pronounce wimmin, womyn, womxn, womban; What’s the origin of these alternative spellings and the problem of feminists adapting gender-neutral and inclusive language?

The internet is a wash with wimmin, womyn, womxn memes, posters and t-shirts. According to the Urban Dictionary the meaning of term womxn is ‘a spelling of “women” that is a more progressive term that not only sheds light on the prejudice, discrimination, and institutional barriers womxn have faced.

But what is the problem with these alternative gender-neutral spellings? Why did this new spelling spark backlash from a section of twitter, reddit and other corners of the internet against it, what is the origin and difference and is it transphobic?