The theory behind inclusive language is that the language we use doesn't just describe the world around us - it shapes our view of it as well. To call the leader of a meeting the chairman is to deny the possibility that a woman can do the job.
Anyone who speaks more than one language recognizes this concept. There are ideas which are natural in one language, and inexpressible in another. For instance, the Ancient Romans had no word for gray. To them, it wasn't a color of its own, just a shade of greeny-black.
English deals very smoothly with such conceptual gaps, either by borrowing words from elsewhere, or by coining new ones. We didn't have a word for savior faire, so someone who needed to express the idea stole the term from the French. Neologisms are all over the place to describe things we've invented since Shakespeare's day, like the internet and its websites.
So why is inclusive language so damn ugly?
There are graceful ways of avoiding gender specific language, like using chair rather than chairman, but there's always someone holding out for chairperson. So many inclusive phrases are grating: spokesperson, herstory, perchild. Nor is grammar safe - the practice of switching the gender of the generic pronoun between paragraphs can make text effectively unreadable.
I finally figured it out. If we make inclusive language easy on the ear, it is effectively transparent. Instead of hearing the language, we hear the meaning. Although graceful inclusive language serves the goal of excluding specifically masculine usages, this is not the true intent of some of its supporters.
Truly effective inclusive language calls attention to itself, reminding the listener (or reader) of the wider feminist agenda. "Look," says the subtext, "I'm being politically correct. I may be talking about running a meeting, but what I'm really thinking about is the historic oppression of women."
Don't do it. It messes up the signal to noise ratio.