I think it is human nature to want to identify with something. We like to show we belong to something...like something. Think wearing baseball caps or shirts of your favorite team, or performer...or Disney character. It's also an identifier to others in the club.
Add the complex nature of a cult, and the feeling of being chosen for a fairytale reward, then ya got near hysterical devotion by some to JW.org.
It is a phenomena we are not used to seeing in the last 20-30 years by the WT though I'll say. I really hate seeing it...but it's my baggage I know.