I've worked at a bunch of SF tech companies, from small to big, and they all had shitty 401k plans with little or no matching. More common now are big end of year bonuses in cash or RSUs.
The 5% matching contributions for the Thrift Savings Plan (gov't 401k equivalent) is one nice part about being in the fed. Not sure if it balances out the crappy GS payscale (especially for colleagues of mine in high-cost areas like SF Bay), but it's something.
Also the TSP fees are much lower than even Vanguard.