How much did Twitter cost to develop vs TIBCO Rendezvous? How much of the "easy" part did you come up with yourself vs working at a polished product that already? What are the actual volumes that Rendezvous handles and how do the details of the network topography compare? How do the details of the functionality compare? How much scalability analysis to they teach in CS (answer: only theory)? Is anyone who doesn't have your particular experience an idiot? Is working on a product for a small collection of the filthy rich better work than creating something that millions of people directly identify with?

Finally, how much do you know about Twitter's architecture and do you know the definition of hubris?