What should be the attitude of a good Muslim towards business practices which are legally allowed (e.g. insurance, stock/share busines, interest etc.) but Islamically incorrect?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The stance of a Muslim towards the forbidden transactions should be that of a person who abides by the Statement of Allaah (which means): {It is not for a believing man or a believing woman, when Allaah and His Messenger have decided a matter, that they should [thereafter] have any choice about their affair.}[Quran 33:36].

Therefore, any system or law which contradicts the Islamic Law should not be taken into account. Anything which contradicts Allaah's Commandments should be disdained by a Muslim. The Prophet said in his farewell Hajj speech: "Everything pertaining to the Days of Jaahiliyyah (Ignorance of the pre-Islamic era) is under my feet (disdained) and is completely abolished, and the Ribaa (i.e. interest and usury) of Jaahiliyyah is abolished…" [Muslim]

Indeed Allaah did not prohibit anything in which there is Ribaa, gambling and deceit except that He opened many doors of lawful earnings, like trading, industry, agriculture, employment, and many other permissible things.

To conclude, the stance of a Muslim towards these forbidden transactions is that he should not involve himself in them and should warn other people against them and their evil.

Allaah Knows best.