First off, good developers are hard to find. I hear many founders complain about this difficulty, so maybe fashion is not the issue. There are many fashion startups that have tech, so it must be possible, right?
Part of the issue may be the way you approach tech cofounders. I know from being approached that, a lot of the time, it just feels bad. It feels like people want to use me. They don't care what I think, they have something, they think it's amazing, and they know exactly how it should work and what the product should be. Like they want to use me for my ability to execute, but don't care for my insight.
Any technical cofounder you would want to have, probably knows what the right product looks like better than you. (you however probably know the market better - your collective challenge is to bring the two together ;).
I'm venting a bit here -- and, trust me, I've heard form people on the other side of the coin and it can feel equally awkward. Potential startup devs have all kinds of issues and things. So I think, in general, it's a difficult chasm to cross and - well, you gotta keep on persevering! But reaching out to techies as partners, listening to what they want to do, and trying to make the venture a hybrid of your two wills combined will certainly make it easier. Tell them you have a problem. Challenge them to solve it, and watch their eyes light up.