So the 5.6 earthquake in Prague was minor to who? you? What about the people who had their houses demolished, lets ask them if it is minor.
This whole story and response reminds me of the movie Outland. Its a Sci-fi movie where people start going crazy and killing themselves and the response by the mining company is "sometimes it just happens around here". But when the sheriff (Sean Connery) starts looking into it he finds increasing frequency of these incidents and they are caused by company supplied drugs to keep workers productive. When confronted people say "hey lets not make a big deal about the deaths, because business is good". Same here, with the wastewater disposal. "Its no big deal", "these earthquakes just happen" and now it is "there are unlikely to be big quakes".