I don't see what Edison being a jerk has to do with that. You think that if Edison had been a nicer person, the x-ray might have been less dangerous?
Plenty of people died at the time due to radiations, including Marie Curie.
The point is that at the time, radiations were thought to be harmless - actually, they were thought to be beneficial, a lot of people would sleep with radium under their pillow for instance. Now, we know them to be harmful.
Likewise, asbestos was thought to be harmless throughout the 20th century - Canada still had active mines in 2009. Yet, now we know asbestos to be dangerous...
In the early 20th century, tobacco was thought to be a good drug - China still have pro-tobacco advertising not a long while ago.
And throughout the 20th, people in the USA have believe that hydrogenated oils where a good and healthy thing, since they were of vegetal origin...
It's not a discussion on Mr Edison personality or of the difference between the different kind of radiation. But it's a discussion about science being an ongoing progress and thus by nature limited in its understanding of the natural laws. The trust is that we don't really know where how harmful or not is continuous exposure to low intensity radiofrequency radiations for decades, because that level of constant exposure didn't exist ten years ago...