"Healthy" is not a weasel word, but one half of a common term that people use[0].
>If someone is paid to literally write code, it's perfectly healthy for them to want to only write code and not provide free labor in a different domain.
It doesn't sound like humbleMouse is getting paid to literally write code. It sounds like they're getting paid to write code and mentor junior developers. It's also not free labor. If someone works 8 hours, gets paid for 8 hours, and spent half of that time mentoring others (which is incredibly generous), then I don't see the issue.
In any case, if someone finds themselves in this position and are unhappy with it, they should talk to their manager or find a new job. There's no shortage for experienced developers.
As a contractor? I have to say I find this doubtful. Without seeing the contract, neither of us can say for sure, but I'd be surprised if it specified mentoring.
Usually "employer" don't know nowhere nearly as much about code as senior devs. If somebody was hired purely to do onboarding, they wouldn't have good grasp on the code either. Seniors who have up-to-date knowledge of the is best bet, no?
If someone is paid to literally write code, it's perfectly healthy for them to want to only write code and not provide free labor in a different domain.
I'd go so far as to say we currently have an unhealthy culture if we're expected to provide free training to everyone.
Job training used to be, and still should, be an explicit responsibility of the employer. Not an underhanded sneak expectation that's unofficially forced on people who were hired for other job descriptions.