In general- option writing for time decay is highly lucrative window shopping deal..
Anyway the big issue is at 2 levels -
1. Many people who do back testing on option writing just do it on expiry prices. So they never knew draw downs on gap ups and gap downs
2. Adding to point 1 - they don't know snapshot max drawdowns occurred on minute to minute basis during volatile moves.
I can say with confidence that most of the back testing's does not cover point 2. So the key is remains that - if the system, traders psyche, traders risk tolerance and appetite levels can hold the drawdown's.