I think it's best to look at the options through a risk matrix. Is it possible that an earthquake is generated by fracking that is big enough to geologically connect a hydrocarbon formation with a surface aquifer thousands of feet above it? I suppose, but I think it is very unlikely. I don't think there are any cases of that on record, and wells have been fracked in the US for many decades (although not as frequently as recently). What is the consequence of that happening? A community (likely a rural community) loses potable drinking water. I would say that is a low probability of a medium impact event.
The calculation is going to change if there is a higher probability of drinking water contamination for whatever reason, or if more people live in the area and would be impacted by an event, just as the risk matrix is different building a nuclear power plant in France compared to building one on the Japanese coastline. Of course every jurisdiction makes its own decisions, as is their right, but the consequence of always taking the least risky option can leave a country in a tough situation when those options don't cover their energy needs, like in Germany (and elsewhere in Europe) right now.
The calculation is going to change if there is a higher probability of drinking water contamination for whatever reason, or if more people live in the area and would be impacted by an event, just as the risk matrix is different building a nuclear power plant in France compared to building one on the Japanese coastline. Of course every jurisdiction makes its own decisions, as is their right, but the consequence of always taking the least risky option can leave a country in a tough situation when those options don't cover their energy needs, like in Germany (and elsewhere in Europe) right now.