The reason I would leave Bitcointalk will be lack of interest in cryptocurrency (as a technology/opportunities it gives)
I considered adding loss of interest as a separate category, but in the end, that also somehow fits inside "Age, family, life, and/or personal problems prevent me from being active". Death.
That's another personal reason to leave the forum. See you in the next life 
Where's option "Theymos/admin remove signature feature" 
theymos never struck me as someone willing to shot himself in the foot. He knows very well the traffic that is generated from signature campaigns as well as the altcoin boards. That's why there is no such option in the poll 