Location also makes a huge difference; in San Francisco (where he lives), median household income is over $65k and the median rental price for a 1 bedroom apart

Location also makes a huge difference; in San Francisco (where he lives), median household income is over $65k and the median rental price for a 1 bedroom apartment is over $2k. If Mok makes $3.5K / month, that probably qualifies as underemployment.