I always assumed they were playing off the old (and in this day and age probably rather socially/politcally incorrect) TV/Movie trope; that any well muscled, hyper macho assertive bordering on agressive male character is either insecure in his masculinity or actually in the closet. I'm not saying it's a good thing, only that it is common, and for all it's progressiveness, MLP:FLM is, for better or worse, not completely free of stereotypes. I mean look at Zecora, Eveyone in Equestria respects her, but the fact is that the one overtly African character in the series spends her time in a creepy forest doing wierd vodoo magic.
While it no longer is as "effeminate" as it might one have been I would also point out that, along with the other "macho" sterotype (Bulk) Iron Will is the only male character in Equestia who wears jewerly. Well except for Tirek, who is also sort of an agressive "uber male" character (I have to assume that, as Iron Will is sentient, he wears a nose ring by choice, not for the reason real bulls used to be equipped with them.)
"For I have heard the Song of War, and to me, it sounds just like "Please, Mister Custer.""
Cogito Ergot Sum, "I think there is something wrong with this rye bread." (Aplogies to Seafrol.)