Did you really say "not backed up by any evidence", and in the very next sentence provide the actual evidence??
If you look at that handy evidence you provided: Magnitude 6 or larger quakes happen 150 times a year. That's about 2 or 3 a week.
And regarding 5.8 magnitude one you mentioned: earthquakes in that range happen about 10 times a day!
Are you really surprised that events that occur this often happen to cluster up on one day?
I'll hold my assertion that it seems to be a more active week than normal in the seismological world.
Your comment adds nothing here and is not backed up by any evidence; "probably every week" does not count as evidence. The majority of the number that the USGS counts includes quakes below the ocean. http://earthquake.usgs.gov/earthquakes/eqarchives/year/eqsta...
The USGS calls anything 6+ "large". A magnitude 6 earthquake can be deadly. Even magnitude 5 < can be deadly. There are factors at work depth of the quake as well as other factors, like location where it hits.
http://en.wikipedia.org/wiki/List_of_deadly_earthquakes_sinc...