The areas in Sweden with railroads are more populated than the Van/Sea/Pdx corridor, by about 1.8x, more if you drop a couple outlying small towns that don't make sense in themselves to connect except for network completeness reasons. Also, railways in Sweden are more middle-speed trains these days, running 200km/h as far as I am aware. These people are proposing 300km/h+ which requires a significantly higher level of track investment - you can't just use standard sleepers and bolted rails.