I'm not saying that I was stronger on the data structures and algorithm side than top students who spent four years staying up coding during their nights and weekends but I was definitely ahead of most fresh grads I encountered. I don't know how that is, given what a typical CS curriculum (at least what I saw later on Open Courseware) but my guess is that a lot of CS grads don't actually practice what they're learning enough so that it sticks.
One thing it appears a lot of people on this thread are missing is that it's not a school for complete beginners. There are prep courses for people looking to enter the school. I had been programming simple things for my blog for years before I went. About 1/3 of my class already had CS degrees before entering.
The other factor is that intensity really does matter. The reason focusing on duration of 12 (well actually 13 weeks) is wrong isn't because nearly 1000 hours of instruction and work are packed into those 12 weeks. It's even more wrong because working at double the intensity leads to more than double the progress. I saw the same phenomenon with language learners when I was living in Taiwan. It's very common for someone who did a full four year degree in Chinese to speak poorly compared to someone else who did a much shorter, more intensive study at a top immersion program like ICLP.
Anyway, the degree of animosity here is a little surprising, even considering the cognitive biases that might come from having spent a fortune on a university credential. Large numbers of my peers from Hack Reactor went on to do well at YC companies and/or large companies like Google. One I remember well did both (was an early engineering hire at a YC company that got acquired by Google). I still consider the tuition I paid to HR one of the better investments I've ever made (and one that I easily recouped within the year.
Thank you Marcus and thank you, Shawn. You guys were fantastic instructors and project mentors!