If we make arrangements for you to work at night, then we'll have to force management to work nights. The majority of people prefer to work days. The traditional business day is the result of an unspoken collusion. There is absolutely no reason why most businesses could not be open at different hours. There would often be benefits to doing so.
Night people are underrepresented in management.
They are overlooked for promotions because their schedules affect their daytime performance. If allowed to work during their prime time and judged on the quality of their work, they would be represented in management in similar proportions as in non-management. Consider what would happen if the same standard was applied to other minority groups, simply to suit the preference of the majority. Suppose a member of an ethnic minority was offered a job only on the condition that they bleach their skin, die their hair blond, and wear blue contact lenses. Most would recognize this as discrimination.