unit linked and non-unit linked policies

I came across a question which was asked i an interview - Why zeroisation is done only with ulips ??

 

Probably because the future expected profit in case of ULIPs are subject to investment returns and are not completely in the hands of insurance companies.
Thus, a need for zeroising.

However, in case of standard plans, the insurance company can design the policy in such a way that it does not encounter negative profits.