Dependencies handling in cmake config

When installing dlib, I see that the exported cmake config has dependencies with hardcoded paths imprinted. This causes any other environment setting to keep the dependencies at the same place.

In my case, I have a docker where I install dlib with cudnn at /usr/libx86_64-linux-gnu.
On the system I want my dlib to deploy to, I have cudnn at /opt/cudnn-7.

Usually cmake allows to abstract from this path-hardcoded dependency by letting dlibConfig.cmake find cudnn a second time (when find_package(dlib ...) is called).

Is there a reason why this flexibility is not implemented? (besides the comfort of not explicitely declaring the dependencies a second time)