You were likely quite right, but the reason is wrong. The reason ought to have been that the best of the "best" day-care centers, even Montessori or Goddard-type repositories, cannot supervise the child as well as a true nanny, and no nanny can achieve in a child what a determined mom/dad can and ought to.
The best kindergarten is the home, if you want your child to love you through obeying you. You and your husband are very foolish if the decision is based on family income.
From 55 years of direct observation and experience.
Day care centers didn’t exist in the mid 60, and 70s. The first time I heard about day care centers was in the early 1980s