Stephen Hackett on Logic Pro X’s skeuomorphic UI elements:
In short, I think Apple views skeuomorphism as acceptable, as long as it’s functional. In Logic Pro X, it is. Dials and knobs make sense in the world of professional audio, so Apple has dials and knobs in its professional audio application.
Sorry, Stephen, wood paneling isn’t functional. The explanation for Logic Pro X’s skeuomorphism is much simpler: there are still loose ends for Apple to tidy up, especially in their desktop software. These plugins to Logic Pro X were clearly designed before Apple switched design philosophies, and rather than take longer to put out this release, they shipped this to be corrected later.