Like, it'sawhat? I also use non camera bags for my gear because of their convenience.
I very often use an ancient, small, and often-repaired, Eddy Bauer canvas bag that can easily hold my Fuji X-T1, an extra lens, spare batteries, etc, as well as a paper note book, phone, and my meds.
When I need more photo gear for a specific event, I have many (too many) bags in too many sizes. But the soft canvas, general purpose bag is what I reach for almost every day.
If I'm going to be mugged, or targeted by a snatcher of man-purses, I don't think disguises will help much. In fact, when I lived in Nicaragua, during the years of the Contra war, I used a big, blue Lowe Pro bag, full of my Nikon equipment, and lots of film. Never had any difficulties with thieves, probably because I knew great people there, and followed their advice.
Yes, thieves carry razors to slice open your bag, but you can use something simple like chicken wire to foil them. And, you can keep your arm around a big shoulder bag.
If I know I'm going somewhere hairy, I do keep the stuff I carry to a minimum, and I wrap either the bag's strap, or the camera's, around my wrist. But - if I'm ever confronted, they can have it all - its insured.