I'm not sure it's worth going into the details of this particular subject again, but if you want to know why some really smart people occasionally leave, consider:

• It's tedious to answer the same types of questions over and over again.
• It's often thankless to answer questions well.
• It's disheartening to see other people rush to post uninformed and, sometimes, completely wrong answers "in the spirit of TIMTOWDI".
• It's rude for someone who asked for free help tell you that your answer is wrong, inappropriate, or not helpful when you're one of the people who wrote, tested, designed, or documented Perl itself to solve that very problem.

Sure, no one's forcing people to contribute here. Certainly, everyone's free to leave at any time. Still, there's little sense in investing time and work on the behalf of people who don't listen to you and don't appreciate you.