How people bond with their friends is by sharing confidences which builds trust between them.
They are not confidences if saying them publicly won't come back and bite you.
> everybody
I didn't say everybody, you don't need to turn it into an absolute to make your point.
I heard about an entertainer for kids who had a radio show back in the day. At the end of one session, he thought the mike had been turned off. But it was still hot, and he groused to the studio "That ought to hold the little bastards for a while."
The goalposts of what is considered career ending is always moving. Something you say today could not be career ending, but it could be career ending when somebody digs up dirt on you in 10 years.
Just look at the whole wokeness movement which has taken root in the last few years and compare what was acceptable to say in 2010 vs what is acceptable to say in 2020.