Jonah, sure, you could make that argument if it was just every once in a while that the scientists were surprised. But it's not just every once in a while, it's quite often.
Science is based on predictions. Predict X, perform Experiment A, observe Result X, and Prediction X is confirmed true.
However, if scientists Predict X, Perform Experiment A, and observe Result Y, then that means there prediction is most likely wrong.
And when it's over and over and over again that journal articles use words like "Jaw-dropping", "head-banging", "socks blown off", "eye-popping", "baffled", "shocked & stunned", then clearly something must be wrong with their basis for their predictions. Here are three examples:
"Unexpected . . . more than a little shaken . . . banging our heads against the wall"... all because their experiment failed to support Darwin's claims, and when they tried to disprove their own work, they failed, and their original research held up.
"No biologist had even the foggiest notion"
"Stunned and stumped . . . defied scientists' expectations . . . blew our socks off"