[soft_dev_person]

> when you pay a musician for a performance, you don't pay them to practice scales

A lot of professional musicians (e.g. permanent orchestra members) are definitely paid to practice scales. A lot of instruments even require training specific muscles to manage playing at all.

For gig-musicians (of any kind), the practice must be factored into the gig payment.

I'd say your analogy is appropriate, but for the opposite point. I don't see any reason for programmers to keep their relevant work skills up to date for free.