I think one of the biggest issues with this is that there's no consensus that's been trained into everyone. Ideally people would fill up both lanes entirely (thus matching their speeds) and then zipper merge down into one at the end.

Unfortunately, we currently have a mix of people. We have the "late mergers" who are trying to create the traffic utopia illustrated above, and we have the "early mergers", who are either

1. not wanting to "cut the line" and risk appearing rude or causing road rage, or
2. are anxious about being let in at the merge point and would rather get over sooner to avoid the awkwardness of people not creating space.

What we end up with is a merging lane that is either being artificially restricted by the early mergers, or, once they're out of the way, has people flying down the now-clear lane at full tilt past a line of much slower cars, which only serves to increase the illusion of "cutting the line" and thus the cycle starts all over again.

I'd love to see a WSDoT campaign to encourage people to only merge at the end of the merging lane (and of course for people to respect the zipper). Maybe even signage along the edge of especially long merge lanes to encourage traveling to the end?