Most people, almost by definition, have rather ordinary tastes. They will want to imagine that it's slightly better than average, but not outrageous.

I don't know much about fashion, but I see it a lot in food marketing. Restaurants differentiate themselves on trendy but safe choices. It works down from the high end: Gordon Ramsey splashes something with truffle oil, and a few years later you can get New Burger King Truffle Fries. A lot of "mom & pop" restaurants are just heating up things off of Sysco trucks.

I don't mean that to sound snobbish. People should enjoy whatever they like. I'm slightly turned off when it's marketed as being really innovative while smaller, more interesting things languish, but that's just the market at work.

As it applies here, I suspect that most people really could be very happy with algorithmically applied clothing. A truly personal stylist would be much more expensive and outside of most people's comfort zones anyway -- unless they did basically the same thing as the algorithm.

What Stitch Fix can offer is the illusion that you're being truly stylish without any of the risks. Which is a fine thing, as far as I'm concerned, if it makes them happy. That excludes a market which really does want a truly personal, human stylist, but I suspect that market isn't nearly as large, and even smaller if you ask them to pay what hours of attention would really cost.