The Imams of Ahl al-Bayt (as) teach that Allah (swt) does not have emotions, as emotions are changing states, and Allah (swt) is above and beyond changing states; therefore, He does not 'get angry' in this kind of anthropomorphic sense.
We can think of sacred laws as being an ideal to which to aspire. It could be argued that all Muslims fall short of fulfiling the sacred law as it should be. A sacred law is designed to keep humanity in harmony with cosmic or universal laws. If a law is not fulfilled, or is violated, then this challenges or violates the harmony that is aimed at, or intended by that law. The consequence of that violation is therefore a kind of necessary cause-and-effect result.
Scholars generally argue that, if someone does not fulfil the law, or violates it, but accepts that the law is valid, then there will be fewer resultant consequences than if they do not fulfil it, or violate it, but argue that they are doing so, because the law is not valid.
There are many reasons for not wearing the scarf - e.g. if your life is danger. Scholars have argued that it is permissible to remove the scarf in these circumstances. In Algeria, women who had been used to being totally covered, including their faces, set aside their hijab to wear Western clothes in order to infiltrate the French quarters of Oran and other locations in Algeria as part of their armed resistence against a colonial regime that had to be removed.
The spiritual consequences of not wearing the scarf therefore depend upon the intention of the person and their reasons for not wearing it.