[Confusion]

One way of discovering what increases property X is testing that some change decreases property X.

Another way of discovering what increases property X is testing that some change indeed increases property X, while also discovering it decreases property Y.

While attempting to increase both X and Y, they made an intermediate with increased X and decreased Y. Perhaps it seemed a promising starting point to also increase Y.

I don't get the surprise. This is all par for the course in research.