It's too bad Amtak isn't flexible or creative enough to protect the frequency on the SEA-EUG portion of the Coast Starlight route. This section (southbound in particular) provides an additional option for travelers on the Cascade corridor.
You have to wonder why it's not possible to simply run the train SEA-EUG and back, using a modified schedule and different train numbers (you could slice off the sleeping and dining cars to lower costs).
The sad thing is they probably come out ahead financially by not running the train, so they don't really have a huge incentive to provide travelers with better options.