because with a pilot strike on a particular airline you can easily book another airline for the same routes but with an airport out of commission all airlines going through there are fucked and the nearest alternative is the airport in shenzhen which requires you to cross the prc border which in turn requires you to go through the fucked up prc immigration and customs checkpoint plus filling up forms for a visa and paying the required fees, not mentioning that you need to find airlines that go to your destination from shenzhen and booking them last minute. you can also rebook your flights not going via hongkang but that may cost more and availability and options are few as it's rebooking last minute. sfo to hkg roundtrip flight is now only $369. some good hotels only $69 per night. cheap cheap at cost. airlines and hotels don't make a dime. best time to go to hk is now.