Issues at a four-way stop can be catastrophic for a motorcyclist. If another driver makes a mistake and proceeds through the intersection at the wrong time, they can cause a devastating accident. Motorcyclists properly riding through the intersection may literally never realize what hit them, as they couldn't anticipate the crash and had the right of way.
One of the most dangerous situations at an intersection is when someone runs a red light. The drivers on the cross street often have no idea they are at risk as they enter the intersection, and many of these crashes happen at high speeds as people try to beat the yellow light and fail to do so.