That article is overly harsh.
Mazin took some artistic license but the show is critically acclaimed and was well executed. It told the story it was trying to tell, quite successfully.
Radiation contamination IS contagious in a general sense. Once an object is exposed and or contaminated, it absolutely can lead to further exposure.
And the only "bleeding" from radiation happens once your skin begins to fall off. Anyone who was shown bleeding at the plant during the disaster was scalded with steam or suffered injury from explosive debris.