My personal opinion, its because earthquakes cant be escaped from, they cover a larger radius that even with running and driving at high speeds the quake would still hit you, while in a volcanic situation an escape can be available by of course driving away. Volcanoes may cause some small earthquakes that can barely do any harm so there are more chances of surviving a volcano than an earthquake. Added to that, earthquakes trap a person on a specific piece of ground since once we move without the sync of the vibration of earth's crust we may fall to the ground which means we should stand still rather than running which may decrease the chances of surviving even less.
Earthquakes can cause damage by shaking, tsunami's, and landslides. Volcanoes can cause damage by ash flows, release of gases, mudflows, lava flows, and landslides. Earthquakes may be associated with volcanic hazards, especially as a precursor to an eruption.
