Well, mostly I would criticize that much of the analysis is based around the cost of making clothing. But buying basic clothing (t-shirts, simple pants etc) is cheap, even from a developing country perspective these days.
In the developed world, we pay for brand, for design, to be fashionable. The price we pay for a garment has only a slight relation to the cost of making the garment. As such, the economics of printable clothing is not going to make a major difference.
In fact it's worse than that. Fashion is often used as a signifier of wealth. If the world discovers that it's expensive to make hand-sewn clothing, and cheap to print it, you can bet your bottom dollar that the wealthy people of the world will only wear hand-sewn garments. These are the people that set fashion, which means that every 20-something fashionista will be looking to copy them, which means that they too are going to have hand-sewn garments. It's the future equivalent of the fact that today's rich and famous don't show up to the Oscars in a jean and t-shirt (well, unless they're trying to make some kind of ironic statement, and even then you can bet that it'll be a designer pair of jeans and t-shirt, costing in the hundreds of dollars)
I'm not hugely fashion-conscious, but I have friends that sit in a bar and tell me whether or not the girl two seats up has a real Versace handbag, or a cheap knock-off (it's scary - enough to make me never buy a knock-off!). If you know what you're looking for, you can see the difference, and people that care about fashion do know what they're looking for.