I think what ruffled so many feathers (and spikes, scales and skins) was the context of the request for guys only. [member="Lysle of the Hydian Way"] summarized the reaction best. Not to nitpick but if the request was done with more context - like, "I want to RP a fight club on a chauvinistic planet, a patriarchy, etc. It will be guys-only because the rulers don't want women fighting, etc." then I don't think there wouldn't have been such a stir.
But the way the request was stated, left room for negative interpretation possibly exclusion of not just female characters but female RPers.
But at the end of the day this should be fun and [member="Darth Vitium"] is absolutely right that we should respect [member="Alberis Nark"] and his right to control the setting as well as his character's outcome.