Yeah, I think the final nail in the coffin for those resisting it was when we finally got good data on the details of the sea floor and we could actually map out the forces that were driving plate tectonics. Also, science in general can be held back by older generations resisting new ideas. IIRC the theory of part of the heat in the Earth's core being caused by radioactive isotopes was basically dead in the water because Lord Kelvin refused to accept it, and his death finally allowed people to really start arguing for it.