This is a rich observation, since (anecdotally) it seems like all the initial customers/traction for YC companies is from other YC companies. Nothing wrong at

This is a rich observation, since (anecdotally) it seems like all the initial customers/traction for YC companies is from other YC companies. Nothing wrong at all, it's good to bootstrap an initial customer base and get some user-feedback, but until the chasm is crossed to "real" customers, one could argue that this is the same case nowadays. So the dotcom time was no better nor worse than right now in terms of startup viability.