No, I do not agree. While it is unlikely that the west coast, more specifically southwest California, will get a Richter scale 9 or higher earthquake, it IS possible. The October, 1989 earthquake in the Bay area was an 8.6. The strongest earthquake so far on record was a .9.6 The 1964 earthquake in Alaska is in the top 10 earthquakes, after Krakatoa and Their/Santorini, which was probably the origin of the Atlantis myth.
The Richter scale is a logarithmic scale, not a linear scale.
What are you going to do when Mt . Ranier wakes up and does a Mt. St. Helen's lateral eruption and wipes out Seattle and Portland with ash?
What is NOT going to happen is part of California sliding into the Pacific. The recent earthquakes were not along the San Andreas fault.