Clients are replaceable and therapists are replaceable. Everyone is replaceable in some ways. One existed before hiring the therapist and one will usually exist after the therapist's engagement. They do need clients to make their living even where they do not need any specific client.
It never bothered me because I never found the therapist to be someone I would like in real life. I could mostly abide the woman for a short time each week. But I doubt she was someone I would want in my real life.