*Sigh*... I remember in the old forums, there used to be one user who posted the "Troll Rankings" every month or so, ranking the top trolls on the forum. Giving people the option to see how many people blocked them feels like it would feed into the competition for achievements among the trolls / spammers of these forums.
It's just another form of self-validation for narcissistic attention-seekers: "I must be so great since so many people have blocked me. Finally, the attention I deserve." Like spoiled little kids who throw tantrums in public and check to see how many adults comply to shut them up.