Shoulders are full of glass and other debris that makes them an intense hazard to ride in. That's why they're the shoulder, not a lane.
In plenty of the areas mentioned (Issaquah, Renton, etc.) there isn't much of a shoulder to speak of. When I take a longer loop around Lake Washington+Sammamish, here's one of the roads I go down:
Looks like enough room to scootch over into if you have cars behind you (just like drivers do for each other). Not saying you don't do that but going back to ggp post, I think it is obstructing traffic that causes the rage. Being flexible can go a long way. If you do make such an effort on your rides, what is your experience with getting yelled at?
Huh? There's perhaps a foot of pavement there. I'm wider than that. My bike is wider than that. There's no room for safely passing in the lane - drivers can go into the oncoming lane to pass just like they would for any other vehicle.
In plenty of the areas mentioned (Issaquah, Renton, etc.) there isn't much of a shoulder to speak of. When I take a longer loop around Lake Washington+Sammamish, here's one of the roads I go down:
https://goo.gl/maps/t9bsNVpJGvFP2sa27