It makes sense that the Bay area would be priced high given its tremendous desirability (which may be tapering off now). If people are willing to work there for low wages, then that is their choice - they have opted into a tradeoff they are OK with, and they/others should not demonize those who were already there and want to preserve their culture/way of life/standards of living. There are numerous affordable places to live in the US that are not [New York, San Francisco, Seattle, etc.] - you may not have every big city amenity you want, or maybe even be able to do the exact job you want - but such compromises are also just a regular part of life, aren't they?
To me the reframing of this issue as a policy problem, or a rich versus poor thing, or through use of pejoratives like "NIMBY" serves to distract from the plain truth, which is simply that people are acting in their own self-interests. And yes, this includes the folks who believe they have an unalienable right to live in the Bay area and demand that local governance be replaced with top-down forceful governance (overriding local zoning policy). And the reality is proposals like the one around the missing middle will not solve the underlying issue - it just shifts the timeline around a bit until population growth brings us back to the same point anyways.