If a scientist isn't able to see data and understand and accept that it disproves a favored hypothesis of theirs, they're no longer doing science. I've seen multiple otherwise great researchers fall into this trap. It's not a new observation, but it's often miscast as scientists needing to be "dispassionate" and "objective" about their data. For me personally, it involves being just as fascinated and excited about being wrong as I am about the times I am right.