Camera brands are a topic that can produce a lot of emotion, from fondness and nostalgia to envy, enmity and even wrath.
I don't care what camera you use, what brand your lenses are. If you're a photographer, I'm cheering for you.
Appraising another photographer by the gear they use or don't use feels like one of the silliest possible pursuits. Photographers love to express displeasure when someone implies that it's the photo gear that does the work (“Oh, this is a great image, you must have an expensive camera”). But all too hypocritically, photographers are also quick to sneer at a fellow photographer's chosen brand of camera or lens.
Good tools enable easier and more fluid work at their best — of course that's true. But beyond that, they're just the means to an end.
I challenge you to judge your fellow photographer by their photos, their character, their contributions to the craft and to the community. These are far more important than the gear brands one uses.