I completely agree with your market forces answer to the salary compensation numbers. So it's not interesting why YC companies are offering salaries like that, rather its more interesting to wonder why they are willing to accept the developers salaries like that filter for.

The developers who would accept those salaries either are a) worth less than the median salary b) don't know their value in the industry c) are naive about the true value of the equity part of the compensation or d) are happy to not maximize their earnings.

All of those filters seem to bias towards inexperienced developers without others who rely on their income (ie young developers from relatively financially stable backgrounds) or those who have no other choices.

So that seems to imply one or more of the following:

- software is the first craft ever where experience does not improve performance.

- writing good software is not important.

- neither is long term team cohesion, as that is very difficult to maintain in the face of chronic underpayment.

So the most likely thing this implies, is that the successes YC companies are shooting for on not predicated on writing long term sustainable good software. Again, there is nothing wrong with that. But I worry that when that isn't explicit it has negative ramifications in environments where writing good software is important for success. If people confuse success as a YC company with success at writing good software they may take the wrong lessons away.