As long as (some of) the airlines can continue to get away with treating PDX like Salina Regional Airport, they will.
Sad but true. I was watching some spotting on YouTube at MIA and it’s amazing seeing all the nonstops coming in from Vienna, Madrid, Milan, etc., but zero from PDX, a 19 million+pax/year airport.
I think one of the main issues is that PDX's airport terminal is way too small, and cannot support too many widebody aircraft at one time. Yeah, concourse E is expanding, but that won't solve the widebody issue, as those will all be regional gates, and that is still not nearly enough of an expansion to make a major difference in the long run.
The only way an expansion will actually make an impact on widebody operations and to entice Delta to consider ICN & CDG, British Airways to LHR, and even far-fetched oddities such as Cathay Pacific to HKG, China Airlines to TPE, Emirates to DXB, and Aer Lingus to DUB is to either greatly expand concourse D, or build a whole new satellite terminal suited for widebody aircraft. Aside from the cost, one of the main problems is that there is very little room for the airport to expand at all, given its close proximity to the Columbia River as well as Interstate 205.
Also, another problem, which is actually quite annoying to me, is that the Port of Portland keeps spending/wasting money by adding completely unnecessary facilities to the airport, such as a Providence express health clinic, a distillery, and a mini-movie theater among many other things. These are NOT things that you normally see in airports. I get that it makes PDX unique from other airports in a positive and quirky way, but in my opinion, that money should be spent on actually expanding the terminals/operations at the airport, like every other city would want to do with/for their airport.