As a male manager of a store that about 80% of our customer base are women, let me say that it is a bit of a balancing act sometimes to provide nice pleasant customer service and on the other hand not to appear too friendly.
That having been said, I don’t understand the question. If your wife feels uncomfortable shopping there, who is forcing her? Convenience? Please, if the cashiers were terribly slow, it would stop being convenient and she would shop somewhere else. Same here, if the manager disturbs you, just shop somewhere else.