It's hard to say which I loathe more. Perhaps what I loathe the most is that the startup atmosphere and the skills that one acquires in tech allow you to do incredible things and make the world better (or at least cooler), but here's something that adds friction to the world economy.
He connects sellers and buyers, just like a grocery store does.
He gives business to t-shirts producers who wouldn't necessarily be able to chose what t-shirts to make, to market them, charge for them, etc. And he helps buyers by giving them a convenient way to order and pay for t-shirts.
Is this much different than opening up a local McDonalds and advertising? Is this really relevant to HN?