I'm uncomfortable with this rehearsal analogy. I'd rather have a company pay me to learn new things than spend my free time coding when I could be seeing my family, pursuing a hobby, or vegging out. From my employer's perspective, I agree that boring is usually better, but as an individual, I'd rather learn on the job than having to feel the need to "rehearse" for my job.
I didn't mean no learning on the job. The time to learn is between projects. If your employer keeps people on projects constantly, then learning happens between tasks.
