For years I have been going to a local tack sale held by a consignment store. Last year an old friend, an out lesbian, came to my barn with a new horse and we headed out to the sale to help her stock up her tack room.
Her impression: wow this would be a great place to cruise, it’s wall to wall dykes with horses. She even ended up meeting an old room mate from back in the urban scene 30 years ago.
I have some gaydar but it tends to be blunted around horse women, where everybody above 35 has become bluff, stopped wearing makeup to the barn, and feels they have to at least pretend to be comfortable with power tools.
Anyhow, it raises the question of how you know that there aren’t gay people in the production and management of the big equestrian corporations?
The question of patronizing small manufacturers is also complicated because while some things (like bedazzled brow bands and fluffy stock ties) work fine as cottage industries, at the other extreme making saddles and riding boots are highly skilled trades that take serious apprenticeship. So there is less choice of vendor.
And things in the middle that are factory produced like breeches, brushes, jackets, saddles pads etc. require a big investment in machinery so it isn’t that easy to find a true independent or small scale manufacturer.
If you are riding Western you can get a handmade saddle from an individual craftsman, and if you are in the right part if the country perhaps that craftsman might be Mexican American. Certainly they might be a source for Iberian or Vaquero gear.
In Canada, the online marketplace is flooded with cheap no name unverified riding helmets made in China and imported, when I checked last year, via India. This is no doubt a small business run by visible minorities, but not something we’d recommend!
Then there is the question of the tack store. Absolutely you can patronize the local independent store whose owners you most appreciate rathet than a chain or online. And you can even buy mostly second hand and call it environmentally friendly 
Within this rather constrained market it could be interesting to see what you could find out about the employment and affirmation policies of the bigger companies and whether there is anyone you really want to avoid.
Of course there is also the realm of service providers such as coaches, vets, body workers, farriers, etc where you can easily select the folks you want to work with.
