The dearth of spirited discussion

[albert_dao]

I would argue that the nature of the internet has changed, and with it, so has the means of dialogue. Let's not forget that it's really only been widely accessible since the late 90's.
It's a bit like the video game industry - look at the type of games that are achieving success now vs. how they were back in the early 2000's.

TLDR - stuff changes.