The 3D view is really interesting (click "Draw Cross Section" lower right), but the main map view is not very useful. Try zooming into New Zealand, or even down to the South Island of New Zealand, and plot a decade start 2007 to 2017. You would be hard pressed to see the two city-levelling destroying earthquakes and one town destroying earthquake we had (Sep 2010, Feb 2011, Nov 2016).
I think the main issue is colour and scale. The magnitude is logarithmic, but the scale of the circles are not.
We experience earthquakes in New Zealand all the time. Th last one was 10 hours ago [1] with a total of three yesterday. So in places you would expect large quakes, you also get lots and lots of small ones.
On a side note, Google beta-tested their early earthquake warning system in New Zealand and it was opt-out. I had students diving under desks in a Deep Learning class because the warning sound emitted was very much like the govt. emergency SMS messages. It was a very minor quake, I am not sure we even felt it.