Perhaps the quakes are relieving pressure that would have otherwise built up over time and produced a real killer quake.
That is more what I tend to think. There is some evidence that there have been major quakes along that fault in the past. There just hasn’t been anything in the last two hundred years. Supposedly, it is a pretty good sized fault capable of producing the “big one”. I would much rather have 3.0 and 4.0 earthquakes several times a year, than one massive 7.0.