If there's a housing crisis...
...then chances are that there's three main causes that apply to any successful city: An excess of well paid jobs relative to current housing supply, exacerbated by poor local government planning to esnure some balance between jobs, housing and transport, and social problems that cause chronic homelessness.
To be fair you can't blame Amazon as such, but introducing the tax would have been an interesting experiment in deterring the sort of jobs that push up property demand and prices, and if it didn't they'd have at least made a move on either getting more money for social housing or social care. My disappointment at the Seattle politicians for their craven surrender is mitigated by a conviction that given more money, local government only waste it unproductively.