I think it is true that men who compete or participate in activities stereotyped as “girly” (ballet, cooking, the arts) can undeniably face bullying and homophobic jokes and prejudice. I’ve seen it myself, even today.
But paradoxically, although it used to be unheard of for boys to say, take home economics, most professional kitchens were still hyper-masculine environments and most professional chefs were male. Boys often had to fight their own families to be in ballet classes, but once trained, they often do have an easier time as pros getting principal roles and get more support coming up the ranks, simply because there are a need for men in certain roles and fewer men ogling for parts. The same is also true in acting–more male roles, yet fewer men training and trying to be actors, and outside the profession a stereotype that the arts are effeminate and bullying, yet inside the profession, often it’s easier to actually make a go of it professionally.
So both can be true. Men can face challenges. But there can also be the attitude of “ooh, a man,” and in the case of equestrian sports, not only is there the novelty aspect there is also the sense the sport gets “legitimacy” (IMHO) if more boys participate at the lower levels.
As a writer, I’ve often regretted I didn’t use an androgynous pen name, as many women do, and in the writing classes I took, although my teachers were often men and the reading lists of my classes full of male authors, there was still emphasis on “encouraging” men to stick with it, because the classes were predominantly female.
It’s frustrating as a woman to work hard and to see that hard work seen as less valuable and constantly questioned and cheapened from the get-go, because it’s more common to see women in your profession.
Regarding actual judging in the equitation, I’d have to disagree first and foremost by O’Hara about women looking more elegant. Jacob Pope is one of the most elegant riders I’ve ever seen IMHO, as well as incredibly sensitive and quiet, and didn’t even come from a professionally horsey family or “money,” just took advantage of many great programs and opportunities.
But T.J. O’Mara’s siblings all rode, and he had unheard-of advantages of many of us will never have, and is incredibly tall and thin drapes over a horse, and it’s much easier for such riders (often men) to look quiet on a horse IMHO than say, short women like Taylor St. Jacques.
I think that any sport judged on the rider like equitation–which is its own weird American thing–is going to run up more against judging bias to “keep men in the sport,” as well as physical bias in favor of a certain physique that can often be easier for teenage boys to achieve.