T. Berry Brazelton was the pediatrician who was featured in the ad, as well as made a paid spokesperson for Pampers at the time. Brazelton was roundly criticized by his contemporaries then and was accused of selling out his professional integrity; gradually, the commercials & ads were withdrawn. Brazelton died in 2018, age 99.
He also curried disfavor by directly telling parents to resist the counsel of grandparents in regard to not only toilet training but childcare in general. That didn't settle with most people, adding to his negative feedback.
Oh, speaking of: I own a teaberry Fruit of the Loom t-shirt. 🤭