Hello! I think it allows for a different technique, mostly.
Interrupted strokes could store information (in this case color). The user might want to intentionally break a stroke, but not reset any gradual change they built into the brush. With color blending, if the stroke is interrupted then the brush reverts back to the original color. This could be a problem for someone using very light pressure (unintentional interruption).
Here's a doodle: