Why can't insurance cover speculative risks, Zhihu?

Need to know the types of risks that insurance companies can underwrite:

The risks that insurance companies can underwrite are mostly pure risks, that is, risks that may cause losses but are not profitable. Generally, they are static risks rather than dynamic risks, that is, risks that may occur under the condition of unchanged social and economic structure. Insurable risk cannot be speculative risk or dynamic risk, because the movements of speculative risk and dynamic risk are irregular, repetitive and weak, and it is difficult to accurately predict and estimate by applying the law of large numbers. Moreover, some speculative risks are prohibited by national laws and unfair to social morality. Accordingly, risks such as fire and explosion are insurable risks, while speculative risks such as stock trading and gambling are not insurable risks. The risks insured by insurance companies cannot be related to illegal activities or conflict with the most basic values or moral concepts of a society.