Exactly. Also, the supply of nurses is highly constrained in the Bay Area due to a very small number of people able to graduate. There's actually a lottery to enter a registered nurse program and last time I checked the odds were less than 30% to win the ticket. Besides that, hospitals lose state subsidies if their nurse/patient ratio drops below a certain threshold. It's really apples-to-oranges.
Not to mention "useful". Imagine nurses going on strike. Now compare that to lawyers, programmers or investment bankers going on strike ... no one cares.
Not to mention an airline. The recent British Airways debacle was caused by a technical problem, but if the IT workers had gone on strike, similar problems could have resulted.