Forbes has a number of such 30 under 30 lists - each one linked in the blog post (Consumer Tech, Enterprise Tech, Food & Drink, etc) is a separate list of 30. So the number of people named to Forbes 30 under 30 this year is greater than 30 total.
Does that seem biased to anyone? It is a business-minded publication, and YC founders are obviously above-average, but surely there are other young founders and entrepreneurs who are deserving of credit as well?