It's not McCarthyism. It's an inquisition. The old compact with corporations was almost feudal loyalty - you support the company, they support you. In the 1980s that changed and corporate morale went into the gutter. The corporations turned to culture. In reality corporate culture is more like a cult.
Google set up to their culture to appeal to people who want to make a difference in the world. One of their cult's tenants is that they are the good guys, righting old wrongs. Google image searches for american inventors, etc. Hiring someone who acted contrary to the culture is like appointing a catholic priest that worships a pagan idol to a devout dioceses. The faithful call out to their high priests for justice.
Issues like this represent very real threats to corporations. Without their faith, employees are only their to cash a check and have zero loyalty to the organization. An org who hires top talent like google starts having retention problems and they lose some of their edge.