What was the problem with the theory of sea floor spreading?

Answer 1

it causes earth quakes under water and some cant be seen because the tectonic plates move so slowly.

Answer 2

The main problem with the theory of sea floor spreading was initially the lack of a known mechanism for how it could occur. Additionally, there was skepticism about the idea of continents moving because it challenged long-standing beliefs about the permanence of Earth's surface features. The theory faced criticism until the discovery of plate tectonics provided a mechanism to explain sea floor spreading and continental drift.