I generally agree with your sentiment, but you should realize that people who live in WA and work in OR still pay OR income tax.
The differences between Portland and Vancouver are particularly stark, as the lack of an urban growth boundary in Clark county (where Vancouver is located) makes real estate (and therefore property taxes) much cheaper on the Vancouver side.
When you get right down to it, my point is simply that people who like a progressive, tax-heavy city like Portland enough to spend a lot of their time there should probably be willing to pay the taxes that go along with that lifestyle. Otherwise, they're just making it that much harder on the full-time residents.