I was thoroughly obsessed with this show when I was in grade school. I now have all five seasons on DVD. It's funny how I can still remember them like they were on yesterday.
Indeed, Sprucemoose, What's My Line was renowned for its civility and urbanity. Proper manners were part of the show. Another example: Host John Daly usually addressed a panelist as 'Miss' or 'Mister.'
After a few seasons CBS wanted John Daly to cut back on the show's polite formalities, but Daly refused. CBS did not press the issue because they feared losing him as a moderator. The CBS version of What's My Line lasted for more than 17 years, so Mr. Daly obviously had the right idea.
I just thought of this. Don't you just love the way the gentlemen always stood up to shake hands with the guests, while the ladies remained seated? My how the custom has changed!