From an evolutionary perspective, if cats hate water so much, why do they love fish? It makes no sense.
There are only two possible explanations:
Cats, like dolphins, went back to the water. After awhile they changed their minds and returned to the land. But they kept their taste for fish.
At some point in the remote past, the earth was infested with, say, walking catfish. Cats developed a taste for fish. The fish went back into the sea. The cats retained their taste for fish.
That's the best I can come up with.