I think the article makes some sweeping and unjustified statements.

Just a few generations ago, everyone knew that there were two subjects not broached in polite company: religion & politics.

This is not true; in many parts of the USA for instance it was (and is) a quite common question to ask someone which church they go to. This might sometimes literally be the third question you get asked right after "what's your name?" and "where do you come from?"

And, of course, many other parts of the world openly debated politics and religion in public and with strangers, and in some places quite often. This is well-documented, and I have personal experience with this since I used to (in the 90's) live in such a country.