Don't edit for the same reason I stay away from Stack Overflow as long as possible:

Less chance of being bitten by people who seems to think they does the planet a service by rejecting and deleting content.

I recognise this might only be a misunderstanding, I rarely get bitten myself but I have seen enough useful questions and answers being punished on SO and enough Meta discussions telling everyone how great this is to learn that the site is mostly not for me.