> If there are good reasons why ... the housing provider would prefer them
Housing is a neccesity in life. Therefore, discrimination by housing providers is a real problem. Being excluded from parts of the housing market is very different from being excluded from parts of the beauty market.
Even more so because housing viable for e.g. white people is equally viable for black people. Whereas the same does not hold for beauty products.
Now, if indeed the other case were to occur (where one ethnicity is not interested in certain housing, and advertising reflects this) that would be less obviously bad. However, like I stated it seems less likely that this would occur. Moreover, this is a very convenient cover for people who do wish to discriminate.